How Do I Trim Ss Screws Accurately And Cleanly?

[rgray]

Here's an old thread with lots of ideas:
http://www.hobby-machinist.com/threads/how-do-you-cut-screws-to-the-proper-length.31267/

 

[kingmt01]

It depends on what I'm standing closer to & what size bolt it is. Something the size of a 10-32 I usually just try to snap it off. If you have a through hole in a plate you can screw it in then smack the unwanted portion sideways with a hammer. If you will never have to mess with it again just start it carefully & forget about it but if you will be removing it & putting it back often then dress the end so it is round & tapered to start easy.

Sometimes two nuts locked then grab the nuts & unwanted part of the bolt with vice grips & snapping it off. Dress the end as needed.

Two nuts on it to line it up in the chuck & face it off or use a hack saw to cut it off. Dress as needed. This is the easiest/fastest way to dress it as well.

Put a nut on it then grind it off.

After seeing Bill's jig I believe I'll add one of those to the project list as well.

 

[PatMiles]

How about a 10-32 die with the screw in it. Position the slot in the die between the chuck jaws so when the chuck is tightened the die clamps down on the screw so it does not move. A caliper can be used between the chuck jaws to measure the screw as it is being trimmed. Small fine file to clean up and round over the fresh cut.

 

[BGHansen]

When I need to trim screws to length of any type, I do it in the lathe.

1. chuck up some scrap that has been turned round and face both ends
   
2. trim it to the appropriate to length
   
3. drill and tap it for the bolt size in question
   
4. pull the stock and thread the screw in, and lock it in place with a jam nut
5. remount it, and face/turn the bolt to length.
6. an optional step is to chamfer the end

I collect Erector sets and a commonly missing part in sets from 1913 - 1923 is a 1 3/8" 8-32 screw. I use Dan's method with stainless screws (look very close to the original nickel-plated screws). The "meat" of an article I wrote for the ACGHS newsletter (www.acghs.org) is attached. Works pretty well with a chunk of steel.

An alternate method was a block of wood and T-nut (pictured in the attachment). Drill the clearance hole for the T-nut and pound it in. Then rip the board with the T-nut up against the fence to get the proper length. Insert the screw and grind away. When the T-nut starts thinning out (if you hit the wheel or belt), pound it out and use a new one.

Bruce

 

[angelfj1]

How about a 10-32 die with the screw in it. Position the slot in the die between the chuck jaws so when the chuck is tightened the die clamps down on the screw so it does not move. A caliper can be used between the chuck jaws to measure the screw as it is being trimmed. Small fine file to clean up and round over the fresh cut.

great idea - thanks

 

[Wreck™Wreck]

Make a screw holder for the lathe like so.
If a RH thread part and chamfer from the backside with the spindle run in reverse so as not to unscrew the parts. If a LH thread run it in the forward spindle direction for the same reason.
The shoulder is for aligning the fixture in the chuck jaws and maintaining accurate Z position, so set carriage stops. Piece of cake.
If you make 2 screw holders one will be running whilst you are changing parts in the second.

 

[KMoffett]

For shortening a few socket head cap screws I too use a Dremel with the red cutoff disks. Put two nuts on the screw. The outer one with the outer face at the point where to make the cut. The inner one used as a jam nut, to keep the outer one from spinning as during the cut. Clamp the head in vise-grips or vise. Use the outer nut as a fence the guide the cut. After cut ting the screw, remove the outer nut. Then chuck the screw head in a battery drill. Set the rotation so the nut doesn't spin off the end. Bevel the screw's end on a belt sander. Run the nut off the end to clean up the end threads.

Ken

 

[gi_984]

I have drilled and tapped a few holes in a block of squared up aluminum in the mill. Ran the screws up from the bottom then taken a few light passes with a endmill along the tops. Fast and easy to do with smallish screws. For bigger I've held them using the nut with the screw thru it and the nut in the lathe's 3 jaw. You can also turn a piece of stock round, drill and tap, then hold in your 5C or 3 jaw. All work well. Just depends on size of the screw/bolts and how fast you want to do them.

This is what I do. I made a 3/8" x 8" steel plate with multiple, common size, tapped holes and then heat treat. One side is SAE and the other is Metric. You need a pretty clean cut (deburred) so you don't screw up the jig[/QUOTE
I've considered doing the same thing Fabrickator did.