Offline category pack · 2026-08-04

Tools, measurement and records

Care and correct use of hand tools, power tools and instruments, and the equipment records that make every other procedure faster.

This is a dated snapshot. Check the current live page and the documentation supplied with your equipment before you start work. Where either differs from this pack, follow the current manufacturer documentation.

32 published pages. Open a title below. Each page is a complete, self-contained HTML file that can be printed from a browser.

  1. Find the exploded parts diagram for a machine you own, and read a part number off itEvery part on a washing machine, a lawn mower engine, or a pressure washer pump has its own diagram and its own number, and almost every repair, cross-reference, or online order starts there. This page shows you how to find that diagram on the manufacturer's own site, using your machine's model and serial number, and how to read it correctly. Reading it correctly matters because the small number printed beside a part in the picture is very often not the number you actually order — manufacturers call that small number a reference, an item, or a key number, and a separate, usually longer number is what goes in the shopping cart. Get that wrong and you can spend money on a part that never fits, or on the wrong part entirely. What this page will not do is hand you a chart mapping one company's part number to another's, or promise that a number you found once will still be correct next year. Manufacturers do replace a part with a new design and a new number, and a part search can keep returning an old number long after the manufacturer has moved on — the only reliable check is to search again, on the manufacturer's own current site, keyed to your exact model and serial number, every time you buy. This page also flags a related risk: parts sold outside a manufacturer's own store or an authorized dealer are, by more than one manufacturer's own account, disproportionately likely to be counterfeit, stolen, or simply the wrong item.Version 1 · updated 2026-08-04
  2. Find the safety data sheet for a chemical product you already own, and read the parts that matterA Safety Data Sheet (SDS) is a standardized document that manufacturers provide for chemical products. It tells you about hazards, safe handling, emergency first aid, and what to do in a spill or if someone is exposed. You can find one by checking the product label for manufacturer contact details, then searching their website or calling them directly. The SDS has 16 standard sections, and knowing which section answers which question is the key to using one correctly.Version 1 · updated 2026-08-03
  3. How do I check if a grinding wheel or cutting disc is safe to use on my angle grinder or bench grinder?A grinding wheel or a cutting disc — the flat, round abrasive stone that fits on an angle grinder or a bench grinder — carries two numbers that matter more than its size: a maximum operating speed printed on its label, and sometimes a date code. Before you fit a new wheel, that speed has to be checked against the tool's own maximum speed, printed on the tool's nameplate, and the wheel has to be inspected and tested for a hidden crack. Skipping either check is how a wheel that looks fine ends up failing while it is spinning at full speed. This page walks through reading both sets of markings, running the tap ("ring") test that catches a crack a visual check can miss, fitting the flanges the wheel was designed for, and running a short test with no load before you put the tool to work. It does not print a table of safe speeds by wheel size — that table belongs to a standard (ANSI B7.1 and its equivalents) that is not public domain, and the maker of your own wheel has already put the number you need on the wheel itself. The point of the page is to teach you to read it.Version 1 · updated 2026-08-03
  4. How do I check if my infrared thermometer is accurate, what is emissivity, and how do I calibrate itAn infrared thermometer is a non-contact tool that reads the heat a surface radiates. Two specifications decide whether that reading means anything and neither appears on the display: the emissivity setting — which is wrong by default on any shiny surface — and the distance-to-spot ratio, which decides how much of the wall or equipment the thermometer is really averaging. This page covers the one field check anybody can make, using an ice bath as a fixed reference point at 0 °C (32 °F). What this page does not do is calibrate the thermometer in the metrology sense — that is work for the manufacturer. What it does is show you whether the thermometer is in the right ballpark for your purposes, and explain two settings that trap readers most often: emissivity and distance-to-spot ratio. A reading taken this way is a check and never a certification.Version 1 · updated 2026-08-03
  5. How do I crimp a wire connector so it does not come loose, and how do I test a crimpA crimped terminal is the standard way to attach a ring, spade or butt connector to a 12 V wire, for a car audio install, a boat, an RV, a solar setup, or similar low-voltage accessory wiring. Done well, a crimp is a permanent joint that outlasts the equipment it is in. Done with the wrong tool, it can look fine and pull apart months later, once vibration and flexing find the weak point. This page walks through stripping the wire, choosing a matched terminal and tool, making the crimp, examining it, and proving the joint with a pull test before you trust it. Every terminal maker publishes its own wire range, crimp die and pull-out force for its terminal families, and those numbers do not carry over from one brand to another. This page does not guess a number for your terminal: it shows you the method, and tells you where to read the number that applies to the part in your hand. It also does not cover fixed building wiring, or connecting the finished lead to a battery or a circuit — those are separate jobs.Version 1 · updated 2026-08-04
  6. How do I decode the date code on my appliance and find out how old it isA dead appliance, a warranty claim, a recall check or a home inspection all come back to the same question: how old is this thing? The rating plate on the back, the door frame or inside a drawer carries the two numbers that answer it, the model number and the serial number, and on some brands the serial number hides a date code that only the manufacturer's own scheme can unlock correctly. This page shows how to find the plate, record both numbers safely, and get a real date, either by reading a date the plate prints directly, by applying a scheme the manufacturer has published on its own website, or by using the manufacturer's own lookup tool or support line. What this page will not do is hand you one decode table that covers every brand, because no honest table like that exists. GE Appliances publishes its scheme, and so do its Café and Monogram brands, so this page cites all three directly. Sub-Zero, Wolf and Cove print the manufacture date on the plate itself, so there is nothing to decode. LG publishes where the year and month digits sit in its serial number, though not which decade a single digit belongs to. Whirlpool, Samsung and Bosch publish no decode scheme on their own support sites, as far as this page could confirm by reading those sites directly, and every third-party chart claiming to fill that gap is unverified by definition.Version 1 · updated 2026-08-04
  7. How do I know if my meat thermometer or fridge thermometer is accurate, and how do I calibrate it?A food thermometer or a fridge or freezer thermometer is only useful if the number it shows is close to the truth. The most reliable way to find out is to test it against a fixed, known temperature rather than simply trust the dial or the display. The easiest fixed point to build in a kitchen is the ice point: a slurry of ice and water, which sits very close to 32°F (0°C). This page shows how to build that test, read it correctly, and adjust a dial thermometer's calibration nut or a digital thermometer's CAL function, on the models that have one. This page will not tell you whether your specific thermometer has a calibration nut or a CAL button, because that is a decision each manufacturer makes model by model, and most digital thermometers have no way for a reader to adjust them at all. It also will not give you a certified calibration to a traceable standard — that is a laboratory service, not a kitchen check. What it gives you is an honest field test: whether your thermometer reads close enough to a known point to trust it, and what to do next if it does not.Version 1 · updated 2026-08-04
  8. How do I know which wall plug or drywall anchor will actually hold what I want to hang?Every wall anchor on the shelf has a number on the package, and that number is almost never the answer to the question you are actually asking. A rating belongs to one anchor, in one wall material, at one thickness, with one screw size, at one distance from the wall. Change any of those and the same anchor holds something else entirely. TOGGLER publishes its own pull-out data for a single all-purpose anchor in half-inch drywall and in concrete, and the concrete figure is many times the drywall figure for the identical part; the manufacturer then says in the same table that the figures are guides only and cannot be guaranteed. That is why this page will not tell you what a drywall anchor holds. What it does instead is teach the method. Weigh the load with its contents, identify the wall material and measure its thickness, look for a stud before you reach for an anchor at all, then read the value for your own material off the manufacturer's data sheet and find out whether it is an ultimate test value or a safe working one. Those two are not the same number, and treating one as the other is how a shelf full of books comes off a wall. Where the load is a grab bar, a handrail, a television or a chest of drawers a child can climb on, this page stops and sends you elsewhere — to the manufacturer of the item, to the CPSC anchoring guidance, or to a qualified contractor.Version 1 · updated 2026-07-29
  9. How do I replace the fuse in my multimeter, and how do I know my test leads are still safe to useA multimeter that still reads voltage and resistance correctly but goes dead only on a current range usually has a blown internal fuse — the small cartridge fuse that protects the meter, and you, if something goes wrong while the meter is measuring current. This is the same problem people describe as a "multimeter fuse blown", a meter that "won't read amps", or one that is "dead on one range", and it is a straightforward fix once you have the exact replacement fuse your own meter calls for. This page covers finding and swapping that fuse, plus a quick check of the test leads themselves, since a cracked or broken lead can produce the same kind of bad reading as a blown fuse. This page gives you the general sequence — confirm the symptom, open the case, swap the fuse, check the leads — the same sequence on almost any handheld digital multimeter with a screw-fastened case. It does not give you a fuse rating: the correct type, voltage rating, and current rating are printed inside your own meter and stated in its manual, and they are different for each model. Fitting a fuse of the wrong rating, or a wire in place of a fuse, defeats the protection the fuse is there to provide. If your meter still won't read current after a correctly rated new fuse, or its case is sealed rather than screwed, this page tells you where to stop and who to contact instead.Version 1 · updated 2026-08-04
  10. How do I set a click type torque wrench and what setting do I leave it on when I put it awayA click-type torque wrench is a spring in a tube. That single fact explains almost everything about how it is used and stored: you set the spring's tension with the handle, you stop the moment the mechanism releases, and you leave the spring relaxed when the tool goes back in its case. It also explains the one piece of advice that gets repeated wrong more than any other — "always return it to zero". You do not. You return it to the lowest number printed on its own scale, and you do not force the handle past that. This page covers the whole cycle: checking the tool, setting a value on the two scales, applying the load, stopping at the click, and winding down for storage. What it will not do is tell you what to set. Torque figures belong to whoever made the thing you are bolting together, and a guessed torque figure is how a wheel comes loose or a casting cracks. Every instruction here traces to Tekton's current product manual or to Snap-on's technical reference, and where those two documents differ — they do, on recalibration — this page says so instead of picking one.Version 1 · updated 2026-07-29
  11. How do I test a fuse or check if a wire is broken with a multimeterContinuity is the one multimeter test almost every household job needs, because it answers a single question: does electricity have an unbroken path from one end of this part to the other? A blown fuse, a cut cord, a failed switch and a dead bulb filament all show the same result on the meter — no continuity — and the same beep tells you a fuse, a switch, a cord or a bulb is still good. This page covers the one setup and the one test, done the same way on any of those four items. Everything here is done with the item unplugged and the part removed or isolated from the rest of its circuit. That is not a suggestion. Fluke, the maker of the test instrument this page is written around, says plainly to turn off circuit power before testing resistance or continuity, and a continuity or resistance test run on a circuit that still has power can damage the meter and shock you. This page does not cover a wall switch, a wall receptacle, or any wiring inside a building's electrical system — that work needs a qualified electrician and a different set of tools.Version 1 · updated 2026-08-04
  12. How do I work out what size bolt this is, and what do the lines on the head mean?Four things have to match before a replacement bolt is the right bolt: diameter, thread pitch, length, and grade. The first three are measurements anyone can take with a caliper, a pitch gauge and five minutes. The fourth is the one that hurts, because a lower-grade bolt looks identical in the hand, threads in exactly as sweetly, holds fine on the bench, and then lets go under load without any warning at all. The only evidence of grade you have in front of you is the marking stamped on the head — and the FAA's blunt version of this, written about aircraft hardware, is worth carrying into a garage: bolts with no markings are low strength. This page will teach you the method and will not print you a chart. That is deliberate and it is worth explaining. The systems that assign meaning to those head markings live inside published standards — SAE J429 for inch-series steel fasteners, SAE J1199 and ISO 898-1 for metric ones — and those standards are copyrighted documents you buy, not facts in the public domain. Procedures and facts are not copyrightable and a marking table is neither. So what follows is how to read a fastener, how to record what you find, and exactly who to ask for the number the marking stands for: the equipment manufacturer first, the standard second. If you came here for a grade chart, the honest answer is that the people who wrote it should be the ones who sell it to you.Version 1 · updated 2026-07-29
  13. How should I store my cordless mower and trimmer batteries over the winter?A cordless mower battery left in an unheated shed all winter is a battery you buy again in spring. That is the ordinary, expensive version of getting this wrong. The rarer and much worse version is a damaged pack put away unnoticed, because a lithium-ion pack that fails does so as a fire, and the place people store them is usually attached to the house. The part of this that surprises people is that the manufacturers do not agree about the most basic instruction, and this page publishes the disagreement rather than picking a winner. DEWALT's storage recommendation for long storage is a fully charged battery pack, and it warns that packs should not be stored completely depleted of charge. STIHL's published answer to 'a STIHL battery should be fully charged before storage' is simply False, and its figure is a charge between 40% and 80%. EGO's own battery manual says to store packs in a 30%-50% charged condition, and to fully charge them every six months of storage. Those are three tier-one manufacturers giving three answers about their own products, and the correct action is to follow the one that made your pack. Everything else here — where to put them, what to check first, what temperature the shed must not reach — is more consistent than you might expect.Version 1 · updated 2026-07-29
  14. How to check if something you own has been recalledEvery product recall in the United States is public, and every recall database is free to search — the hard part is knowing which agency covers your product, and what to search by. This page teaches the general skill: gather your product's manufacturer name and model number, choose the right database, then search by product category, by manufacturer, and by date. It uses the Consumer Product Safety Commission's own recall register and recalls.gov, the single government site that also links to the recall lists for food, drugs, cosmetics, and more. This page does not cover motor vehicles, tires, or car seats — those are searched by VIN through a separate government database, and the VIN and recall check on this site walks through that search instead. If your search here turns up a match, the next step is simple: stop using the product and contact the manufacturer for the repair, replacement, or refund the recall notice describes.Version 1 · updated 2026-08-04
  15. How to clean and store hand tools so they don't go rustyRust on a hand tool is almost never a failure of the tool. It is water, left on bare steel, in a space that spends half the year damp. The fix is a ten-minute routine at the end of a job — get the dirt off, get the tool completely dry, put a thin film of something on the steel, and store it somewhere that is not the coldest corner of the garage. The part worth reading carefully is which product goes where. Channellock's published answer is blunt: you can use WD-40 to surface clean pliers, but not to lubricate the joint, because it strips the grease out and makes a tight joint worse — use 3-IN-ONE oil in the joint instead. Leatherman, asked the same question about its own pivots, names a PTFE or Teflon-based lubricant. Those are two manufacturers giving two different answers for the same part of the same kind of tool, and this page does not average them into a house recommendation. The storage advice comes from a different direction. The National Park Service publishes what it takes to stop steel corroding in a collection store, and the numbers are instructive even though nobody runs a garage that way: it is the relative humidity that matters, cold spaces are worse than warm ones because of condensation, dust holds moisture against the metal, and foam, felt and wool are named as sources of the sulfur that tarnishes metal. That last one is a surprise to most people lining a drawer.Version 1 · updated 2026-07-29
  16. How to find and record the model and serial number of every appliance in the houseAlmost every useful thing you can do with an appliance starts with its model number. Checking whether it has been recalled, ordering the right part, booking a repair, claiming under a warranty, proving a loss to an insurer — all of them need it, and all of them need it at the worst possible moment, when the machine is already broken or the recall is already in the news. This page is the boring hour that makes those moments easy. Do it once for the whole house, keep the record in two places, and you will never again be lying on the kitchen floor with a torch trying to read a label behind a dishwasher. What this page will not do is tell you where the label is. That varies by manufacturer and by model, and it varies within a single product class: two CPSC refrigerator recalls describe the label as being on the top left of the interior in one case and on a serial plate inside the compartment in another. So the location is published here as an instruction to look, with the usual hiding places listed, rather than as a fact. The other thing worth knowing before you start: a recall notice identifies affected units by model number and by a range of serial numbers, so recording only the model number gets you halfway and can leave you guessing about your own machine.Version 1 · updated 2026-07-29
  17. How to find your car's VIN number and check if it has an open recallThe VIN — vehicle identification number — is a 17-character code that encodes information about your vehicle's manufacturer, model year, plant of manufacture, and specific unit. It is the key to checking whether your vehicle is subject to an open safety recall. This procedure walks you through finding the VIN on your vehicle, reading what each section of the VIN tells you, using the official NHTSA VIN decoder to understand the encoded information, and then searching the NHTSA recalls database to find out whether any safety recalls apply to your specific vehicle. A recall that has not been repaired is a safety risk; the manufacturer provides the repair at no cost. The NHTSA (National Highway Traffic Safety Administration) maintains the authoritative database of vehicle recalls for the United States. This page routes you to that database and teaches you how to interpret what you find there.Version 1 · updated 2026-08-03
  18. How to measure a pipe or a hose so the fitting you buy actually fitsA pipe or a hose is sold and labeled by a nominal size, and a nominal size is a name for a product family, not a measurement of the object in your hand. A pipe marked half inch can measure five eighths of an inch across, a garden hose fitting marked three quarter inch is sized by an old thread standard rather than by a ruler across the opening, and the gap between the label and the measurement is different for every material. Buying a fitting from the label alone is one of the most common ways a repair trip to the store turns into a second trip. This page shows you how to read the measurements a fitting seller actually needs: the outside diameter, whether a thread is straight or tapered, and the thread pitch. This page teaches measuring and identifying, and it stops there. It does not print a table that converts a nominal size into a measured one, because that conversion belongs to the pipe or the fitting manufacturer and differs by material and by standard. It does not cover cutting a pipe, installing a fitting, or sealing a joint. It does not cover gas pipework at all; that work goes to a licensed plumber.Version 1 · updated 2026-08-04
  19. How to read the label on a power tool and understand what the numbers meanEvery power tool carries a rating plate, and most owners never read past the model number. The same plate lists the electrical rating your tool needs to run, the speed the motor reaches with no accessory fitted, the biggest accessory the tool can safely take, and the marks that show how the tool guards you against electric shock. Reading it correctly is the one page every other power tool page on this site assumes you have already done. This page will not print a voltage, a current, a speed, or an accessory size for your tool, because every one of those figures belongs to your own model and no other. What this page teaches is which field to look for, what a marking on the plate actually means under OSHA rules, and where the real answer lives: on the plate in front of you. Write the numbers down, and take them to a professional whenever a repair calls for a matching part.Version 1 · updated 2026-08-04
  20. Identify a battery from the code printed on it, and find the right replacementA dead remote, a dead smoke alarm, or a dead flashlight usually comes with one clue: the tiny code printed on the old cell. That code is doing several jobs at once — it names the chemistry, it points to a physical size, and it implies a voltage — and two codes that look almost the same on a shelf can be genuinely different cells. Buying by a rounded label like “AA” or a guess at “the round one” is how the wrong cell ends up in a smoke alarm or a key fob. This page shows how to read the printed code correctly and compare it against a replacement, using real examples read directly from cell manufacturers’ own datasheets. What this page will not give you is a single chart mapping every code to every “equivalent.” The numbering system behind these codes is set out in a paid international standard this page has not read, and a chart copied from a retailer or a hobbyist site is unverified by definition. What it gives instead is the method: read every character of the code, compare the chemistry letters against a manufacturer’s own datasheet, check the voltage, and buy a cell with the identical code whenever one is available. Button cells and coin cells carry a serious swallowing hazard for a small child, and that hazard comes first on this page, before any step.Version 2 · updated 2026-08-04
  21. Identify a lost power adapter from the equipment's own marking, and match a replacementYour equipment carries a label with its power requirement. The label lists four things: the output voltage, the current capability, the polarity (whether centre pin is positive or negative), and the connector type. Find the label, read these four items, then search for an adapter that matches all four.Version 1 · updated 2026-08-03
  22. Measure how hard your water is, and know what the number meansA water hardness test strip gives you a fast, rough number for how much dissolved calcium and magnesium is in your tap water. Dip a strip, wait, and match its color to the chart on the container to get a reading in milligrams per liter (mg/L), parts per million (ppm), or grains per gallon (gpg). This page walks through collecting a fair sample, running the strip correctly, and reading the color chart without guessing between two blocks. It also explains what the number means, using the U.S. Geological Survey's own classification for soft, moderately hard, hard, and very hard water. Hard water is not a health hazard — it just carries more dissolved minerals, which can leave scale in a kettle, a coffee machine, or a steam iron, and can make soap harder to lather. This page tells you how hard your water is and what that number means. It does not size a water softener, recommend a softening chemical dose, or replace a certified laboratory test. A test strip is accurate enough to plan maintenance; for a softener purchase or a suspected water quality problem, use a laboratory test or ask your water utility.Version 1 · updated 2026-08-04
  23. Measure the moisture content of firewood with a pin moisture meterA pin moisture meter measures the water content inside firewood by detecting electrical resistance. Wood that has been properly seasoned (dried) contains 20 percent moisture or less and burns efficiently without producing excess creosote. This procedure explains how to select the correct location on a firewood piece, insert the meter pins, read the measurement, and apply a species correction if your meter does not do it automatically.Version 1 · updated 2026-08-03
  24. Read a tape measure, and understand why its hook is meant to be looseA tape measure looks simple, but two things trip up almost everyone: the small marks between the inch numbers, and the metal hook at the end that wobbles. That wobble is not a broken tool. The hook is riveted with a small amount of built-in play, moved back and forward by a distance equal to the hook's own thickness, so a reading comes out the same whether you hook it over an outside edge or push it flat against an inside wall. This page shows how to read the whole-inch numbers and the fraction marks between them, how the hook's built-in movement keeps outside and inside measurements accurate, and what to do when the hook cannot sit flush. It does not certify how accurate your own tape is; a separate page covers checking a tape measure against a known length.Version 1 · updated 2026-08-04
  25. Read the yellow EnergyGuide label, and know what its number does not includeMost major appliances sold in the United States carry a yellow-and-black EnergyGuide label: refrigerators, dishwashers, clothes washers, freezers, central air conditioners, furnaces, heat pumps, boilers, pool heaters, water heaters, room and portable air conditioners, and televisions. The label sits inside the appliance door, on the front of the appliance, or on the box, and it puts two things in front of a shopper: a dollar figure for the estimated yearly cost to run that model, and a yellow scale showing where this model falls between the cheapest and the most expensive model like it. A separate blue ENERGY STAR mark sometimes appears on or near the label, and it is not the same thing. The dollar figure is not a preview of your utility bill. The Federal Trade Commission says so directly: it is only an estimate, built from typical use and a national average price for energy, not your household's habits or your local rate. This page explains where to find each part of the label, what the estimate assumes, and what it leaves out, using the FTC's own consumer guidance and the FTC's and ENERGY STAR's own descriptions of the two marks. It does not publish a cost for any specific model or for your home — only the label on the appliance in front of you, and your own utility bill, can give you that.Version 1 · updated 2026-08-04
  26. Tell a metric hex key or socket from an imperial one before it rounds the fastenerA hex key or hex socket is sized by the flat-to-flat width of its tip, and that width comes from two unrelated systems: whole or half millimetres, or fractions of an inch. Several sizes in the two systems sit close enough that a key from the wrong system can slide into a fastener and feel almost right. A 5/32 inch key is only 0.03 mm from a 4 mm fastener; a 5/16 inch key is only 0.06 mm from an 8 mm fastener. That gap is smaller than a human hair. Force the wrong one and it can ride up on the corners of the fastener instead of gripping the flat sides, and either the fastener or the key can be damaged before you notice the size was wrong. This page gives a repeatable way to tell the two systems apart: read any printed size, then measure the tip, then compare the reading against the exact millimetre-per-inch figure published by NIST — arithmetic you can check yourself, not a table borrowed from somewhere else. It also gives a fit test for the moment before you turn anything, because a size can look right and still not seat flush. What it does not give is a single master chart that tells you which sizes belong to your own set: sets vary, and a low-cost set is not always cut to the nominal size in the first place, so the reader is sent to a measurement, not a guess.Version 1 · updated 2026-08-04
  27. Use a feeler gauge to measure a clearance, and find the figure it should beA feeler gauge is a set of thin metal leaves that measure gaps and clearances between engine parts, bearing surfaces, and adjustable components. Using it correctly means finding the leaf that fits with a light, consistent drag through the gap. Once you have the measurement, consult your equipment manual to find what the clearance should be for your specific model or application.Version 1 · updated 2026-08-03
  28. What NRR do I need for ear protection with power tools and a lawn mower?Hearing loss from tools is not dramatic and that is the whole problem with it. There is no pain, no bruise, and no moment where you notice it happening — you notice it years later, in a restaurant, when you cannot follow a conversation. NIOSH puts lawn mowers, vacuums and power tools at around 85 to 90 dBA, and chain saws among the things that average 95 dBA or higher. Those are not exotic numbers reserved for a factory floor. They are a Saturday morning in the garden. This page does three things. It gives you a way to estimate how loud your equipment is without a meter, using NIOSH's own published voice test. It sets out both federal exposure limits — NIOSH recommends 85 dBA over eight hours with a 3 dBA exchange rate, OSHA permits 90 dBA over eight hours with a 5 dBA exchange rate — and it does not merge them, because they are different by design and knowing which one you are working to is the point. And it shows what to do with the NRR printed on the package, using OSHA's published arithmetic rather than a rule of thumb, alongside NIOSH's own position that the printed rating often does not reflect the protection an individual person actually gets.Version 1 · updated 2026-07-29
  29. What drill bit and what speed should I use for wood, metal, plastic or concrete?Most people pick a drill bit by looking at the hole they want and pick a speed by squeezing the trigger until it sounds about right. The bit choice is usually recoverable — a wood bit in steel just goes blunt. The speed choice is the one with a safety rule attached, and Milwaukee states it plainly in its drill manuals: never operate at higher speed than the maximum speed rating of the drill bit. That means the drill has a number, the bit has a number, and one of them has to stay under the other. This page teaches you to find both numbers on your own equipment and to compare them in the right direction. It does not print a drill speed chart. The three manufacturer manuals read for this page publish speeds and bit limits per model and not as general guidance — two Milwaukee drills that take the same bit in steel are rated for a 2 inch hole saw and a 3-1/2 inch hole saw respectively — so a single chart would be wrong for somebody. Where the number is yours rather than ours, this page says so and sends you to the document that has it.Version 1 · updated 2026-07-29
  30. What dust mask or N95 should I use for power tool dust, and how do I know it is not fake?A disposable dust mask, often sold as an N95, is the everyday answer to sanding, sawing, cutting and grinding dust from a power tool. Not every dust mask on a shelf is actually NIOSH-approved, and a growing number of counterfeit N95 masks carry a printed approval number that does not exist on the government's own list. This page shows how to pick a filter class for the job, and how to check a respirator's approval number before you trust your lungs to it. Is a dust mask enough? For ordinary wood, drywall and household dust, a genuine N95 usually is. For concrete, brick or stone dust, the hazard often includes silica, and heavy or long exposure can call for more than a simple disposable respirator and a professional judgment call. This page does not cover gas masks, cartridge respirators or supplied-air equipment, and it does not replace a workplace respiratory protection program where one applies.Version 1 · updated 2026-08-03
  31. What size blade fits my circular saw, and does the RPM rating on the blade matter?Most people buy a circular saw blade on two numbers: the diameter and the size of the hole in the middle. Those two get the blade onto the saw. They do not tell you whether it is safe there. The number that does is printed on the blade in smaller type — the maximum safe operating speed — and it has to be compared against a number printed on the saw, which is the no-load RPM on the nameplate. Milwaukee's instruction is blunt about the direction of that comparison: only use blades with a maximum safe operating speed greater than the no load RPM marked on the tool's nameplate. The reason this catches people out is that saws which take identical blades do not run at identical speeds. Two Milwaukee 7-1/4 inch saws in front of us take the same 7-1/4 inch blade on the same 5/8 inch arbor, and one turns at 5,000 RPM while the other turns at 6,300. A blade that is comfortably inside its rating on the first saw is over it on the second, and nothing about the fit tells you that. This page walks the four numbers in order, says what to do when any one of them does not agree, and stops at the point where the answer is to buy a different blade rather than to try it and see.Version 1 · updated 2026-07-29
  32. What size filter do I need, and is a generic or cross-reference filter really the same as the OEM part?Two things identify a filter: the part number printed on its own frame or housing, and its own physical dimensions. Between them, they let you test any “compatible,” “generic,” or “will fit” claim before you spend money on a filter that turns out to be the wrong size or the wrong shape. This page covers HVAC and furnace filters, refrigerator and other water filters, cabin air filters, engine air filters, vacuum filters, and pool or spa filters — anywhere a reader stands in front of a wall of near-identical boxes trying to work out which one is actually theirs. What this page will not do is hand you a cross-reference chart mapping one brand's part number to another's. A chart like that is either the manufacturer's own parts list — which you can get directly, for your own equipment, and which this page shows you how to use — or it is a third party's compilation, which is unverified by definition and which we will not publish as fact. What you get instead is the method: read the marking, take the measurement, and compare both against any candidate before you buy or install it. The filtration rating and the replacement interval for your specific equipment stay on that equipment's own page, not here.Version 1 · updated 2026-08-04