Glossary

30 terms

Words that turn up on the reference pages and inside finder results, explained without jargon.

Fasteners

6 terms

JIS vs Phillips: Two cross-head recesses that look nearly identical and behave differently. A JIS recess has a flatter root and lets the driver seat deeper, and it is usually marked with a single small dot punched into the head beside the recess. Driving a JIS screw with a Phillips bit loads a narrow band near the top of the recess and rounds it out, which is the standard way a screw is ruined on a Japanese-built vehicle or camera.Read onScrew Drive Types and How to Tell Them Apart Precision Bit Sizes by Device Class Bit Finder
Cam-out: The driver climbing out of the recess under load instead of turning the screw. On Phillips fasteners this is a design feature rather than a fault: the tapered flanks were shaped to make the driver lift above a certain torque, back when limiting torque any other way was expensive. It becomes a problem when it happens early, which points to a worn bit, an undersized bit, or the wrong drive family altogether.Read onScrew Drive Types and How to Tell Them Apart What to Do With a Stripped Screw Bit Finder
Pentalobe: A shallow recess with five rounded lobes and no center pin, used on phone and slim laptop cases. It comes in a 0.8 mm size on phones and a 1.2 mm size on laptops, and those two are not interchangeable. A Torx bit of roughly the right size will enter a pentalobe recess and turn about a quarter turn before the rounded lobes give up entirely.Read onScrew Drive Types and How to Tell Them Apart Precision Bit Sizes by Device Class Bit Finder
Tri-wing: A recess with three wings set off center, like a pinwheel, found on handheld console shells and battery covers. It is routinely confused with tri-point, which has three legs at even 120 degree spacing and looks like a Y. The two are not interchangeable in either direction, however similar they appear in a photograph.Read onPrecision Bit Sizes by Device Class Screw Drive Types and How to Tell Them Apart Bit Finder
Gamebit: A hollow tubular bit with a square cut through it, used on retro cartridge and console shells. It comes in 3.8 mm and 4.5 mm sizes and nothing else substitutes for either. The larger bit will not enter the smaller socket, and the smaller one turns loosely in the larger and shears the post inside it.Read onPrecision Bit Sizes by Device Class Bit Finder
VESA: The standard hole pattern on the back of a monitor or television for wall and arm mounts, given as a spacing in millimeters such as 100 by 100. Knowing the pattern tells you the bracket will bolt to the screen, and it tells you nothing about whether your wall will hold the result. That second question is an anchor and a stud question.Read onAnchors by Wall Type Shelf Load Planner

Garage openers

4 terms

Rolling code: A scheme where the remote and the opener agree on a new code after every use, so a code captured off the air cannot simply be replayed. Chamberlain Group documents rolling code generations against Learn button colors, with red or orange and purple both described as Security+ rolling code at different frequencies. Which generation you have affects what a replacement listing needs to say.Read onGarage Opener Learn Button Colors and What They Mean Garage Remote Model Numbers, and Which Number Is Which Remote Finder
Learn button: The button on a garage opener motor unit that puts it into programming mode so it will accept a new remote or keypad. Chamberlain Group documents it as sitting on the same side of the opener as the door control and safety sensor wiring, and publishes a chart tying its color to a technology, a frequency and a year range. The color fades with age, so it is worth checking against the antenna wire color and the programming LED before relying on it.Read onGarage Opener Learn Button Colors and What They Mean Remote Finder
Security+ 2.0: A Chamberlain Group coding generation, documented against a yellow round Learn button and covering roughly 2011 to 2025 across two entries in the published chart. The chart names more than one frequency for it, so the color alone does not pin down the radio in your opener. A newer white round button is documented as Security+ 3.0 over Bluetooth from 2025.Read onGarage Opener Learn Button Colors and What They Mean Remote Finder
Dip switch: A bank of tiny physical switches inside older remotes and openers, set to the same pattern on both so they recognize each other. Because the code is fixed rather than changing after each use, dip switch systems predate rolling code entirely. If your remote has a row of small switches under the battery cover, that is what you are looking at.Read onGarage Remote Model Numbers, and Which Number Is Which Garage Opener Learn Button Colors and What They Mean Remote Finder

Loads

3 terms

Static vs dynamic load: A static load rests on the shelf; a dynamic load arrives at it. Shelf ratings describe the static case, because that is the easy one to test and the easy one to survive. Setting a 40 pound battery down firmly applies a force well above 40 pounds for the moment of contact, and the shelf sees that peak rather than the average.Read onWhat a Shelf Load Rating Actually Means What Garage Items Actually Weigh Shelf Load Planner
Shelf deflection: How far a shelf bows under load, which is a stiffness question rather than a strength one. A shelf can carry its full rated load and still sag enough to be useless, and no capacity rating describes it. A sagging shelf makes bins slide toward the middle, which concentrates the load further and increases the sag.Read onWhat a Shelf Load Rating Actually Means Shelf Load Planner
Anti-tip: A strap or bracket fixing a tall unit to the wall so it cannot rotate forward. It is not carrying the load, so its rating is about a sudden force rather than a steady one, and it belongs in a stud rather than in hollow drywall. CPSC runs a national campaign on furniture and television tip-over because this failure lands on people, most often children.Read onWhat a Shelf Load Rating Actually Means Anchors by Wall Type Shelf Load Planner

Pressure

9 terms

NPT: National Pipe Taper, the tapered thread standard used on air fittings in the United States. A quarter-inch NPT fitting is what most compressor lines and inflator gauges use, so it is the thread that decides whether a gauge meets your hose without an adapter. The taper is what seals, which is why NPT joints are done up tight rather than to a face.Read onANSI B40.1 Accuracy Grades Gauge Picker
Bezel: The ring holding the lens onto the face of a dial gauge. It matters more than it sounds, because a bezel that has been knocked loose lets water and grit reach the movement, and a gauge with a disturbed movement can read wrong while looking perfectly normal.Read onANSI B40.1 Accuracy Grades Gauge Picker
ANSI B40.1 Grade A and Grade B: Accuracy grades for dial pressure gauges, stated as a share of the full span rather than of your reading. Grade A is documented as 1 percent of span across the middle half of the dial and 2 percent in the first and last quarters; Grade B is 2 and 3 percent. The B40.1 designation was consolidated into ASME B40.100, so listings citing B40.1 are citing a superseded name.Read onANSI B40.1 Accuracy Grades Gauge Picker
Hysteresis: A gauge reading differently at the same pressure depending on whether it arrived from above or below. It comes from friction and elastic lag in the mechanism, and it is the reason a needle that has been let down to a value can sit a little off from one that was brought up to it. Tapping the gauge face is the traditional response and it works for exactly this reason.Read onANSI B40.1 Accuracy Grades Gauge Picker
PSI vs bar: Two units for the same quantity. One bar is about 14.5 PSI, so a 2.2 bar figure on a European placard is roughly 32 PSI. Gauges sold with multiple unit settings switch between them, which is convenient and is also a way to misread a tire by a factor of fourteen if the display has been changed and nobody noticed.Read onCold Pressure, Placard and Sidewall Gauge Picker
Placard pressure: The recommended cold inflation pressure printed on the vehicle tire information placard, usually on the driver door jamb. NHTSA describes it as set by the vehicle manufacturer from the design load limit and the tire size, which is why it belongs to the vehicle rather than to the tire. This is the number that governs what you set.Read onCold Pressure, Placard and Sidewall Gauge Picker
Cold pressure: Pressure read before the tire has been driven on or warmed by the sun, which in practice means first thing in the morning or after several hours in shade. Driving heats the air inside and raises the reading, so bleeding a warm tire down to the placard figure leaves it underinflated once it cools. Ambient temperature alone moves pressure by roughly one PSI per ten degrees Fahrenheit.Read onCold Pressure, Placard and Sidewall Gauge Picker
Schrader valve: The wide valve with a spring-loaded pin in the middle, used on cars, light trucks, trailers, motorcycles and many mountain bicycles. Almost every gauge sold in a general store has a Schrader head, which is why it is the default assumption in tire equipment. Pressing the pin releases air, which is how a gauge reads and also how you lose pressure by fumbling the seat.Read onCold Pressure, Placard and Sidewall Gauge Picker
Presta valve: The narrow bicycle valve with a threaded tip you unscrew before inflating. A Schrader-only gauge head will not close on it, so a car gauge is useless on a road bicycle regardless of what its scale reads. That is a separate problem from range, and road bicycle pressures of 80 to 130 PSI put most pocket car gauges out of scale as well.Read onCold Pressure, Placard and Sidewall Gauge Picker

Tools

8 terms

S2 steel: A tool steel used for driver bits, hard enough to hold its shape at very small sizes. It matters most on precision bits, because a bit that deforms slightly under load starts behaving like the next size down and rounds the recess it was supposed to turn. A steel claim is a hardness claim, not a guarantee that a particular bit was manufactured to its stated callout.Read onScrew Drive Types and How to Tell Them Apart Precision Bit Sizes by Device Class Bit Finder
Chuck: The clamping jaw at the business end of a drill or driver that grips the bit. Keyless chucks are tightened by hand and are the norm on cordless tools; keyed chucks grip harder and need a separate key you will eventually lose. A chuck that lets a bit slip under load is worn, not badly tightened.Read onScrew Drive Types and How to Tell Them Apart Kit Checker
Torque: Turning force, which is what a driver actually delivers to a fastener. It is the product of force and the distance from the axis, which is why a longer handle turns a tighter bolt with the same effort. Almost every ruined recess on this site is a torque problem meeting a fit problem: the fastener needed more than the contact area could carry.Read onScrew Drive Types and How to Tell Them Apart What to Do With a Stripped Screw Bit Finder
Hook and loop: The two-face fastening used by reusable cable straps, where stiff hooks on one face catch soft loops on the other. It fails by contamination long before it fails by wear: sawdust, grit and pet hair pack into the loop face and stop the hooks engaging. A stiff brush recovers most of it, which is why a strap that lives on a garage floor does not last.Read onStrap Width and Length by Bundle Kit Checker
Magnetic tip: A driver tip magnetized so it holds the screw while you position it, which matters when the fastener is 1.2 mm across and the alternative is losing it inside the device. It does nothing whatsoever for fit. It also collects swarf, which then sits in the recess and holds the next bit out of full depth.Read onPrecision Bit Sizes by Device Class Bit Finder
Cushion grip: A handle with a softer outer layer over a hard core, so you can push hard without the handle digging into your palm. That matters more than comfort suggests, because downward force is what stops a tapered bit climbing out of the recess. Cushion material perishes before the steel does, and a handle that has gone tacky no longer lets you push.Read onWhat to Do With a Stripped Screw Kit Checker
Ratcheting driver: A driver whose handle turns freely one way and drives the other, so you never let go of the fastener to reposition your hand. On a socket ratchet the tooth count tells you how small a swing is enough to advance the fastener, which is what matters in a space where the handle cannot travel far. Ratchets are also the part most likely to fail, and one that skips under load has worn pawls.Read onBench Height by Task and Height Kit Checker
Impact rated: A bit made to survive the hammering action of an impact driver, which shatters ordinary bits. The difference is in how the steel is treated: an impact bit is allowed to flex slightly rather than being hardened to the point of brittleness. A bit that has driven impact fasteners should be retired from precision work whatever it looks like.Read onWhat to Do With a Stripped Screw Screw Drive Types and How to Tell Them Apart Bit Finder