# Shortening screws



## deverett (Feb 17, 2009)

Here is a simple gadget to shorten screws to a uniform length, shown with a brass screw shortened:












Size is about 2-3/4" x 1-1/4" but can be whatever size you want. Each step is 1/16" high. Mine caters for BA 4 - 8 sizes.

Saw off the excess piece of screw and file off any bit not taken off with the saw. When the screw is removed, any burr will be cleared.

The holes are for countersunk as well as round/hex head screws. Tap each hole for the required thread and then drill out clearance to leave the last couple of threads only. This saves lots of twiddling of the screws in and out. It is best to nip up the screw in its hole otherwise it can back off when it is being sawed.

The base could be casehardened, but this one has lasted about 15 years without hardening.

Dave
The Emerald Isle


----------



## Mark-One (Feb 17, 2009)

Nice!

I thought up a *very* simplified and crude form of that last night because I need to shorten some #4 set screws (for until I can order in the proper length ones). I was just going to drill and tap some steel rod, set them out the right amount and stick em against the grinder ;D

Your jig is much nicer.


----------



## shred (Feb 17, 2009)

Mark-One  said:
			
		

> Nice!
> 
> I thought up a *very* simplified and crude form of that last night because I need to shorten some #4 set screws (for until I can order in the proper length ones). I was just going to drill and tap some steel rod, set them out the right amount and stick em against the grinder ;D
> 
> Your jig is much nicer.


That's what I do.. one day I'll make a cool jig like that, but my current method is a little strip of CRS with a tapped hole in it and hold it to the grinder. Works well on small screws under about #10, but is annoying on larger ones or if trying to make a bunch exactly the same length-- that's where the screwplate like Dave's really shines.


----------



## cfellows (Feb 17, 2009)

That's a nice solution for a common problem. I usually by small screws in lots of 100 in 1/2 or 3/4 inch length, then cut them off as needed. My method involves nippers to cut them and the belt grinder to smooth out the end. Not very accurate. For bigger screws, I use a dremel tool with a cutoff blade. I'll have to make up one of these jigs.

Chuck


----------



## Mike N (Feb 17, 2009)

I have a jig just like yours but I use my vertical belt sander to grind off the ends. Even if I need to remove a 1/4" of material it comes off fast on small screws.

I chuck up screws in my cordless drill & spin them up against the belt sander, if I only have a few to shorten, this really works good to round off the ends also.


----------



## lathe nut (Feb 17, 2009)

Thanks Dave, another one on the to do list, that is a great Idea, better than my cave man way of doing them, Lathe Nut


----------



## BillH (Feb 17, 2009)

I use a dremel with a cut-off wheel.


----------



## Tin Falcon (Feb 18, 2009)

Most of the time I cut mine with a wire stripper/ terminal crimper screw cutter thingie. I good one not a cheapie. 
Tin


----------



## Kermit (Feb 18, 2009)

Thats so simple! and so much smarter and better than the "put three nuts on a screw, hold it with pliers and put it to the grinder" method I have used.

Do you have any plans, so I could make one?    



_that's a joke_,
Kermit


----------



## Noitoen (Feb 18, 2009)

Those universal crimping pliers used in the automotive repair shops, have a series of threaded holes next to the hinge so you insert a screw to the required length, cut and when you remove it the hardened thread cleans it out nicely. ;D


Helder


----------



## Captain Jerry (Feb 18, 2009)

Attention!!!!!

When using the stripper/crimper thingy to cut a large screw like a #8, it may take two hands and a heavy grip. Be sure that the meaty part of your thumb is not between the stripper jaws as you squeeze. When the thing finally bites thruogh the screw it may jamb. This then requires two hands to spread it open and if one of your hands is gripped firmly and painfully in the stripper jaws, you may wake all the dogs in the neighborhood before you get it open.

Don't ask. . . . . . . . . . .

Jerry


----------



## itowbig (Feb 18, 2009)

captain j been there done that. i now use the vice for clamping down on those pliers :big:
i too need to make on of those . i seen one very simler to that here some where some body showed one they made ;D


----------



## Noitoen (Feb 18, 2009)

Captain Jerry  said:
			
		

> large screw like a #8



In mm please. ??? ??? My pliers goes from 2.5 mm up to 6 mm and cuts "normal" screws with ease. The hard ones I don't even try.


----------



## mklotz (Feb 18, 2009)

Noitoen,

The formula for the size of American numbered screws is:

OD (inches) = 0.060 + 0.013 * N

where N is the screw number.

Screw numbers run from 0 to 14 although 7, 9, 11, 12, 13, 14 are very rarely seen. There are also sizes smaller than zero such as 00, 000, 0000, etc..

Can you believe that we still use this idiotic measurement system? It's almost as stupid as our three systems for designating drills - fractions, letters and numbers.


----------



## max corrigan (Feb 19, 2009)

When i was apprenticed at Fairey Aviation many many moons ago, somebody thought up one these tools for cutting rivets.it was the same as the tool pictured, but had a hardened square bar pivoted on one end you poked the rivet through the appropiate length hole pulled the bar (lever) and cut the rivet perfectly to length every time,of course these were mainly dural or ally rivets, but i've know doubt it would work on other small rivets
Max..............


----------



## GailInNM (Feb 19, 2009)

Most of the time I turn off the excess length using a split bushing in a collet in the lathe. Split bushings are quick to make up and I have quite an assortment of them. In the photo , notice the top hat left on the end so the bushing stops on the face of the collet. I just split them with a band saw. Drill the hole for a snug clearance fit on the screw. Often when the bushing is split it closes up a little bit but driving a wedge in it (screwdriver) will open it up.

Gail in NM,USA


----------



## Noitoen (Feb 19, 2009)

mklotz  said:
			
		

> The formula for the size of American numbered screws is:
> 
> OD (inches) = 0.060 + 0.013 * N
> 
> where N is the screw number.



After some "research" I found this. http://mdmetric.com/tech/tic1c.htm It explains a lot.

Helder


----------



## bentprop (Feb 19, 2009)

I'm a bodger. :bigrill a hole in required thickness piece of scrap,tap,insert screw.Clamp the whole mess in the vice,and wallop the end off the screw with a cold chisel.smooth end of screw on belt sander.done.


----------

