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Need to source type of steel bolt for welding a finger lever onto

helmbelly

Aluminum
Joined
Mar 12, 2013
Location
New Orleans
I can't source "clamping levers" off the shelf that work so plan to weld my own levers to a hex bolt or threaded rod. I have never welded anything but have a small Lincoln machine and can prob figure it out. What material bolts /rod will weld best to a low carbon steel finger lever I shape up myself? The shaft is 2" x 5/16 thread. The finger lever is 2 x 3/8 x .125 low carbon steel. What materials will weld up and quench well? Many thanks !
 
You want the cheapest, lowest strength grade of steel bolt or threaded rod in order to be compatible with your similar low carbon steel lever. For safety, it is best not to weld plated steel parts without good ventilation. Quenching has no effect on low carbon steel, but might not be a good idea on a red hot weld. Silver brazing steel with a gas torch is a lot easier to master to the point of neat results than electric welding.

Larry
 
Well thanks Larry. I've been curious about welding so innocently thought welding would be the way. I'll look into silver brazing online. I should also look at hardening low carbon steel maybe I used "quench" incorrectly - I meant to heat it up blue and douse in water or oil. Thanks for your reply.
 
There are ways to harden just the surface of low carbon steel, called case hardening or nitriding. If you need the whole part to be hard, you need to use medium or high carbon steel with or without additional alloys. And the method of joining gets more complex if you want to heat treat after welding. You do not heat treat steel parts that are silver brazed.

Larry
 
Welding Gr5 fasteners to mild steel is a common thing. Just get it hot.

If it's to support your Mother In Law..........stick to a strict WP(preheat, interpass temps, post heat, and proper filler material)...........................If it's for a set of clamps.........just weld it.
 
Any flux core wire, or 7018, will suffice. It won't hold the Brooklyn Bridge, or anything critical (your MIL), but it will probably still be there 20yrs from now.

You can get all technical, and start talking about the HAZ, but it's not critical for something like this.

I'm as anal as the next guy about carbon uptake, or Hydrogen embrittlement, but it's generally not an issue with a clamp. Welding dogs are welded to mild steel all the time with no disastrous outcomes.

Is it correct????????? No. Is it expedient, and common? Yes.
 
Last thing you do is quench a weld. The only hope of survival is a slow cooling process. You actually want to keep the heat in the joint for a protracted period after the weld is made. This lowers the stress placed on the parent metal as the weld cools.

Post heat, or slow cooling, allows the bead to contract slower............reducing hot cracking.
 
Good to get real world advice with no bickering over the 4th level of molecular entropy. I'm making a 50 piece batch run for a product that hand clamps to bike handlebars (1.25") I was having trouble getting a no slip clamp with 1/4 20 bolts so moved up to 5/16 and it's working. It's a 2 bolt saddle clamp, one bolt you tighten down with a wrench and the other one needs the hand lever (wing nut basically) so it's adjustable. I like the idea of brazing bc it will look better, and low cost cheap steel seems offer all upside for this. I think I'll try brazing with a propane torch on unplated bolts. Plan to test .065 and .125. I just have a small prototyping shop unsure of the most low impact way of slicing up thin steel into strips. Have a good geared band saw but thinking about getting an old beverly shear.
 
If the propane torch seems to get it done, I'll get acetylene which should make it faster, cleaner.
I found an old yellow can of real MAPP in my mom's garage in Maine but I'm too chicken shit to mail it down to myself. Afraid to land on the news for blowing up some mail carrier.
 
I have made a lot of single or double lever bolts using various bolt grades including SHCS's, basic hardware store crap bolts and graded bolts depending on what is at hand. Since the weld itself is very little stressed, following ideal procedure for welding is not required. I have yet to have one fail. I usually do not temper the weld area by post heating the weld.

One of the easiest ways to make such a lever bolt is to simply through drill a hole in the 1018 bar the same diameter as the bolt. Cut the head off the bolt. Insert the cut end in the hole. Then I MIG, Tig, or silver solder the two together.

Something like this:
1699885486728.png

1699885543501.png

Variations are to bend the wings up at a 5 degree angle or so for clearance or to just add a single wing. Sure beats having to find a wrench to simply adjust a bolt that simply prevents a sliding bar from moving.

No way would I be so casual about welding a bolt that actually was under load, especially a bolt whose failure might matter.

Denis

BTW, those images above ACTUAL PHOTOGRAPHS of the perfection of my MIG and Tig welds:D
 
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wow dgfogster, I mean wow. I never envisioned something that clean. You need to apply a little muscle to my clamps so I'd prob cut the bolt head then slot the shaft to accept the arm on it's side from your "photograph". I wonder how thick would the levers need to be? Think I can go much below .065? Thanks for sharing such a great approach.
 
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I'm going to order some 2" strips of steel after I settle on a thickness and make some up dgfogster style (meaning perfect ;-) I have a good old geared Delta band saw but dont like the idea of sawing 100 of these - or would say a 14 TPI carbide band saw blade slice steel like bread? Kinda wondering if an abrasive wheel or a Beverly shear might be the thing. I'm not happy unless I expand my tooling with every job ;-)
 
Prob is the kip levers break if you apply any force and they hurt your hand trying - and they are usually about $10 per. I've bought a lot of them to test - never found one I like
I wish they'd just make some simple T and L levers where you could choose the length of T and L. Maybe this is my future in the industry bc it's really pissing me off I gotta go cut and shape 100 little popsicle sticks!
 
wow dgfogster, I mean wow. I never envisioned something that clean. You need to apply a little muscle to my clamps so I'd prob cut the bolt head then slot the shaft to accept the arm on it's side from your "photograph". I wonder how thick would the levers need to be? Think I can go much below .065? Thanks for sharing such a great approach.
So, I am surmising you want to place the cross arms vertically (in their weak orientation) so that it is more comfortable to put some force on the bolt? If I needed to add "pads" the cross arms, I think I would consider finding some round or even rectangular steel or aluminum tubing that might fit over the arm. That's because it seems you'd need a pretty thick piece of bar stock to resist bending and yielding if vertically oriented. So, I am guessing a 3/8X3/4 vertically oriented might be equivalent to 1/8X3/4 horizontally oriented. (Some engineer will probably blow that wild guess right out of the water.) I really think the vertical design just goes counter to our usual sense of design or "it just does not read correctly."

But instead of all the complexity of padding the flat bar cross member, I think I would simply use a piece of adequately sized round, square, or rectangular tube as a cross bar and attach it again by inserting the bolt shaft and welding it in place. That would have excellent strength and good broad bearing surface for the hand. [And it looks right ;-) ]

Denis
 
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All thread and a wing nut. Cut all thread to length, thread the wing nut on leaving a 1/16” recess. Plug weld.
might even get away with flush threading, some loctite, and a solid center punch smack on the thread/nut edge.
Wing nuts are already nicely debured.

Do not waste money on carbide bandsaw blade. Your saw does not have the rigidity those blades need, or the Umph/control to push that blade to its advantage. For 100 parts not sure I would even worry about exact tooth count. A standard bimetal 10/14 blade cuts at 14 ipm up to 3/8 stock- without even pushing it or overspeeding.
 
That would have excellent strength and good broad bearing surface for the hand. [And it looks right ;-) ]
Again wow. Really good. Round or square answers the hand pinch problem and eliminates all the pre machining to relieve edges, and as you say - stronger and better looking. So that is drawing 1. Drawing 2 is what I meant by flipping and slotting. It's clear to me that 1 is superior in every way but curious wise- I would think if arm in drawing 2 was .065 thick with 5/8 of bearing surface in the slotted bolt, the overhang would be .687 on either side. I would have guessed that 1/16 thick steel would be overkill. Just thinking out loud, thanks again
 

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All thread and a wing nut.
The clamp has to be bejesus tight to not slip on a bike handlebar - need much more "arm" length than wingnut to get the force w/o hurting your hand
A standard bimetal 10/14 blade cuts at 14 ipm up to 3/8 stock- without even pushing it or overspeeding.
Thanks I have only cut steel on the bandsaw geared down a couple times without good results. Last time the blade was 5-6 TPI for thick aluminum. I need to get a blade just for steel.
 
Just thought of rust. If I braze an alum arm on top of mild steel bolt like sketch 1 above- I can't anodize the part. Since it will be used in the weather it needs plating. Maybe make everything from 304 or another SS? It seems SS is brazable ok. If I attach alum to stainless can stainless go through the anodizing run if they are pre-assembled? Brazing post anodizing sounds like a bad plan.
 
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