Making a flow forming tool
 

I want to make the flow forming tool for my rivet gun I have a metal lathe so making it is not the problem I'm not sure what's the best steel to use to make it as far as the inserts I'll get them from Kent any help would be appreciated I already made one by cutting the shaft from an air chisel and brazed a socket to it but now I want to machine it out of one piece thanks in advance ed

Ed, personally i wouldn't recommend the welded or brazed approach. I've used 3 air chisel shanks and welded on various ends using different methods each time. All worked for several hours, but ultimately failed at the weld through fatigue. In the end I purchased a billet shank from Sky Lowrider on here. He makes beautiful shanks from 4140 heat treated steel and also inserts for Flow forming. All were not expensive and were beautifully crafted. Highly recommended 👍

Look for Lisle 39300
https://www.amazon.com/Lisle-39300-F.../dp/B000CSFBWW

I turn my inserts out of delrin. Turns beautifully and tough as hell.

This rig does everything I need

I'll respectfully and completely disagree.

Properly brazed tools are extremely durable and are the industry standard for carbide faced impact tools. Every job I carve in stone is produced with carbide tipped steel shank chisels. This includes bushing tools (commonly called 4 points or 9 points) that are used perpendicularly against the face of the work to pulverize away material. That's far more brutal circumstances than moving relatively thin metal against much less resistance.

Properly built tools will not fail at the brazed joint. The end (carbide or otherwise) may fracture- usually from becoming too thin or from improperly applying an edge of the tool instead of the properly central face- or the tool shank may fail- usually because of poor quality steel, inadequate dimension and/or improper heat treatment.

imho it's a lot easier to braze (ribbon silver solder or whatever high nickel rod I have, can't remember) a special tool, especially if I then need to heat treat the tool. any thin cross section chisel shank will suffer injury or failure more quickly if subjected to high temps of welding and then not properly treated. Even properly tempered tools can break if you bind them. One of my air biggest air hammers (jib mounted surfacing machine) will easily and quickly break a perfectly good 1" diameter tool steel shank if you bind it. very exciting.... Pretty sure that one will flow form heavy plate but haven't gotten that far yet..

For nearly 20 yrs I have made, worn out and remade thousands of carbide tipped impact tools. They only fail when I misuse them or when I did a poor job making one (Metallica was probably on the radio when I was building that one...). The few flow forming tools I made up with steel ends attached to old short machine chisel shanks- much quicker to braze one up than to forge one and no lathe here yet- are just as dependable...

Thanks for all the replies , I don't have a problem with the brazed joint failing I still use it atleast a couple times a week and I've had it for atleast a year or two I just need a longer one I figured why not start with the correct material thanks again ed

Thanks for posting the link. How do you secure the delrin to the tool?

I turn the delrin so it fits into the Lisle tool

My solution to a long lasting version of this is to bore a hole in a bar stock piece not all the way through so as to have the end of the chisel bit fits tight in it. Now weld this to a thin wall piece of tubing either round or square depending on the product you choose to use for your forming . I also weld a nut so to use a set screw to pinch against the insert. Streck Tools also has a similar tool that is made of a composit material that has a hole for a chisel bit in it. I drove the bit out the end and started ruining the panel I was trying to form . After doing this to multiple pieces and having Streck nicely replace at no cost I finally contacted their Tech guy and he asked what I was using for a hammer source and of course proudly stated I was using Snap Ons bad boy These are way too powerful for this process as well as most rivet guns as their piston is too heavy and not needed for flow forming. I looked in the back of the droor for an old cheap muffler gun and that was the answer

I agree with all methods, above. It all works to whack metal, one way or another.

Attachment 41217I just bought the cheap HF chisel set and welded a washer for good measure probably didn't need to since it cut the sharp end off and deburred it ,drilled the UHMW a little undersize and put the bit in the zip gun and drove it in made sure there was over an inch left of UHMW will take awhile to beat thru and cheap enough to start again