Brass is an alloy of copper and zinc, and the relative proportions of metals in the alloy can vary according to manufacturer specifications and the required mechanical functioning of the screws. In these sorts of scenarios, grub screws might often need to be drilled out for proper removal, which can be challenging in itself due to the high tensile strengths of materials generally used to manufacture grub and set screws. Reading the fine print often makes telling statements about the manufacturer’s confidence in their own product. I guess that the grafite grannels was alittle bigger for more grapping power on the screws would work alittle better.

Grub screws for this purpose are especially widely used in architectural ironmongery, and are a very common feature found wherever door handles are attached to spindle shafts.Also, the instructions say to proceed immediately, I waited nearly a minute to proceed and I put it on thick. Because they’re fully threaded and designed to be driven into an existing tapped hole or socket - rather than driven into the surface, creating a new hole - they’re commonly considered a type of bolt, albeit with a few key differences.

Because they often feature no protruding screw head in the traditional sense, true grub screws tend to be driven by means of a sunken internal recess at what is still generally referred to as the ‘head end’. The screw head just looked like a crater, that's how damaged it was and how we apparently purchased it!They can also be driven with considerably more torque force than traditional screws, as the uniform diameter right the way along the full length of the grub screw shaft means that they don’t begin to split the hole apart as they go in further. In most cases with UK suppliers, you’ll generally see sizes given in the format akin to ‘M8 x 12mm’ or an equivalent variant with different numbers. As well as in architectural ironmongery, grub screws are often used in a wide range of industries and sectors to secure all manner of collets, gears and handles to their respective mounting brackets or hardware. One potential downside of flush-set grub screws, however, is that they can be quite difficult to remove once driven with full force to sit flush with or countersunk into the surface of the workpiece, especially if they do become corroded or the drive slot is damaged due to excessive torque going in.

First off, this flat screw was SO STRIPPED, I didn't even realize it was supposed to be flat, I had to look at the manual for this pulley lamp we'd gotten from Costco 4 years ago. This is especially the case if the drive recess has been damaged during insertion, or where corrosion has occurred around the threads. Because grub screws very often feature a recessed hole or slot at one end for a hex drive, Allen wrench or flat-head screwdriver - as opposed to a traditional head - they can be awkward to get sufficient purchase on for easy removal.

Wish I'd taken a picture of how screwed the screw was but it was inset pretty deep, might not have been evident in the pics.