Interesting bolt found

[Pearldrummer7]

Just thought I'd share this. No one at the office can determine what the purpose of having a bolt shaped like this is. Found this guy at work and don't understand it's use. Does part of it break off at a certain torque or something?




Edit: nevermind! Someone at the office informed me that it's from a lock core for different door thicknesses. Pretty cool.

[first time builder]

Similiar to toilet flange break away bolt.

Kenny

[Ray]

Not sure about that, but I have this bolt chart in the shop.....

bolts.jpg

Ray

[NBinSD]

I thought of the same toilet flange bolt when I saw that... I used a couple of them this weekend.

Ray I love your chart... I need some of those!

[frankeeski]

We use those type of bolts/machine screws all of the time. Cabinet hardware sometimes comes with them, sometimes not. We use them mostly in the 8/32 size. We measure length and break them off. The way we did it previously was to use a screw cutting tool. This is the tool we use to cut threaded machine screws without messing up the threads.
http://www.kleintools.com/catalog/co...-tool-8-22-awg



Did you find it in a cabinet drawer?

[myjones]

We use those type of bolts/machine screws all of the time. Cabinet hardware sometimes comes with them, sometimes not. We use them mostly in the 8/32 size. We measure length and break them off. The way we did it previously was to use a screw cutting tool. This is the tool we use to cut threaded machine screws without messing up the threads.
http://www.kleintools.com/catalog/co...-tool-8-22-awg



Did you find it in a cabinet drawer?

The size and shape of the head and the bolt give it away. The doorknob screw shown above have that smaller slightly thicker head that tightens against a metal plate. I have hardwared thousands of commercial doors so I'm very familiar with that unique fastener.

Another cool fastener is the (wing) tek screw. It is made for screwing a wood substrate to metal framing up to 1/4" thick. It has a self drilling tip them two crimped wings then a side cut for beginning the self tapping threads and some even have a second set of wings up by the head to self countersink. The drilling tip bores through plywood, then starts boring through the metal stud or bar joist flange and at that point the wings bore a bigger hole in the plywood then they snap off when they hit the steel leaving a bigger hole in the plywood so it will pull down tight instead of binding on the fastener threads and lifting itself away from the steel. With those wings snapped off it bores the right size hole in the steel and cuts it's own threads as it pulls down. Saves a lot of time and steps while leaving a good finished product.

[tirod]

I was a commercial locksmith as well as a bidder for architectural hardware and hollow metal frames for eight years. That is a bolt for a lockset that adapts to different door core thicknesses.

Residential and commercial specs for doors and hardware have about zero overlap - household doors are less than 1 3/4" thick, have a 2 3/8" backset, use 3 1/2" hinges often with radius corners, typically run less than 36" wide and usually 80" tall. And as many pastors of large churches have discovered, those specs do not meet commercial code for large buildings with attendance in the hundreds, not will they meet ADA standards.

Commercial specs are 1 3/4" doors with 2 3/4" backset, handles must have a return to allow thumbless operation (NO knobs,) doors are usually 36" wide (meets ADA use for wheelchairs) and 84" tall. Hinges are 4 1/2" and if a closer is installed must have bearings. Doors must swing OUT in the direction of egress so that people will not be trapped when panicking from a fire alarm. It's a very old standard dating back to a catastrophic fire in a New York theatre in the early 1900's, and still ignored by club operators who routinely chain the exits to prevent crashers getting in.

A bolt as shown for use with either set of standards is one that would likely be a better grade for residential, but very poor for commercial. The difference in usage is exponential. The front door or bathroom door in a home might be used up to 30,000 times a year, in a commercial installation 250,000 times a year. If you frequent a commercial building and see residential grade knobs on a bathroom door, you are seeing the owner throwing his money away.