How we size, drive and store fasteners
Short notes from the bench: choosing a metric screw kit, measuring a screw, installing threaded inserts in wood and in 3D prints, reading a set screw, what a screw eye can hold, and the dowel-rod trick burglars hate.
How to choose a metric screw assortment kit
A metric screw assortment kit is only useful if it carries the sizes your repairs actually use. Here is how we decide what goes into a Hapric box, and how to pick the one that matches your…
How to install threaded inserts in wood
Threaded inserts for wood turn a tired hole in a chair rail, table legs, a bed frame or a plywood cabinet into a permanent, reusable metal mounting point. The installation takes a drill, a hex wrench and five minutes if…
Set screws: 304 stainless steel vs 12.9 alloy, and how to size one
Set screws hold knobs, levers, collars and pulleys to a shaft, and they are the fastener most often missing when something spins free. Two questions decide the right one from a set screw assortment: what steel, and what…
Heat set insert tips for 3D printing: hole size, depth and temperature
Heat set insert tips for 3D printing, in one page: a heat-set threaded insert gives a printed plastic part a real metal thread. The insert is brass, knurled on the outside, and a soldering iron with a tip of the right…
How much weight can a screw eye hold?
Short answer: a nickel-plated screw eye from a hardware kit holds a picture, a plant or a string of lights in solid wood, and it is not rated for lifting anything. The long answer is about the wood, the thread…
Why do thieves hate dowel rods?
The question comes up in every home-security thread, and the answer is simple: a wooden dowel rod laid in the bottom track of a sliding glass door or window stops the panel from sliding, whatever happens to the lock.…
How to measure screw size: diameter, length and thread pitch
A screw size is three numbers: diameter, thread pitch and length. Measure all three and you can identify a lost fastener and find its match in any kit on this site. Here is the method we use at the bench to measure…