Any problems/advantages using 1018 CRS vs A36 for AXA/BXA toolholders?

turdferguson6400

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Hi, I need to make a bunch of regular and some special AXA and BXA tool holders. I've read all the posts I could find but I'm still unsure of what steel to use.

I'll have access to a milling machine for a few more weeks at the community college where I'm taking classes.

In my area, I can get 1018 cold rolled for about 20% more than A36 hot rolled. 4140 Annealed is 2-1/2 to 3 times more expensive. I don't think I can afford it!

Initially I was going to use 1018 CRS so that squaring the bar would be easier. But I've read that if CRS is machined, it can warp due to internal stresses. So then I thought of A36 hot rolled which is more stable but more work to square.

It looks like the mechanical properties of 1018 and A36 are similar.
https://www.capitalsteel.net/news/blog/a36-vs-1018-steel-comparison

I'm going to be buying steel tomorrow so any answers would be appreciated.

Thanks!
 
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Yes, cold rolled will warp if you machine one side and not the opposite side. There is no real problem if you take off approximately equal amounts on both sides. Also, with something that is blocky (like a tool holder) as opposed to something long and thin, you probably wouldn't notice warping even if you did just machine one side. It depends on your tolerances.

If I'm making something where I can buy the stock such that it is the correct size in a couple of dimensions, then I'll use cold rolled. If I'm going to be machining most of the surfaces anyway, then go with hot rolled.

Having said that, I recommend you spend the extra for the 4140. The cost of the material is minor compared with the time you will spend making and using the tool holder. You don't want to be saying for the next X number of years, "I wish I had done it right at the beginning."

Hi, I need to make a bunch of regular and some special AXA and BXA toolholders. I've read all the posts I could find but I'm still unsure of what steel to use.

I'll have access to a milling machine for a few more weeks at the community college where I'm taking classes.

In my area, I can get 1018 cold rolled for about 20% more than A36 hot rolled. 4140 Annealed is 2-1/2 to 3 times more expensive. I don't think I can afford it!

Initially I was going to use 1018 CRS so that squaring the bar would be easier. But I've read that if CRS is machined, it can warp due to internal stresses. So then I thought of A36 hot rolled which is more stable but more work to square.

It looks like the mechanical properties of 1018 and A36 are similar.
https://www.capitalsteel.net/news/blog/a36-vs-1018-steel-comparison

I'm going to be buying steel tomorrow so any answers would be appreciated.

Thanks!
 
What I was planning to do was get a 18" long piece of 3" wide and machine the dovetail in the center. Then chop this block into shorter pieces to make each individual tool holder.
 
I believe most are case hardened so a premium like 4130 is not normal.
OXA holders I built, I used hot rolled and they look and function just fine.
I think if I remember right I milled the tool slot in a length, rather than the dovetail. My thinking was to minimise the use on the dovetail cutter.
 
What I was planning to do was get a 18" long piece of 3" wide and machine the dovetail in the center. Then chop this block into shorter pieces to make each individual tool holder.
I had the same idea, and bought the metal, but then found nice store bought holders for ~$10 each. I have about 15 of them now, and they all work well, no muss, no fuss. I still have the material if I want to make some custom ones. I was planning to do the same thing, cut the dovetails in the entire length of the part. More experience has made me think more about that idea. The dovetails need to be quite accurately dimensioned to work well, and a little loss of tolerance can make them scrap. Will your milling machine hold tolerance to a couple thou over 18"? Have you tried to do something like that? At the very least, if I was starting it today, I might rough cut the entire bar and then cut them to length and finish cut them individually, which could go pretty quickly, and with a lot less chance of scrapping a nice chunk of metal.
 
I'm going to get a bar 12" long of 1"x3" or 2"x3".

Then use an end mill first to cut a slot in the center of the 3" face(parallel to the 12") and then widen the slot using the dovetail cutter to the proper width. Measured with .250" pins and an adjustable parallel.

I need some that aren't available commercially at a reasonable price.

I've done a prototype an the machining seemed to be accurate enough.
 
I bought some 1018 to make some. I want to make some that support more extension of the HSS tools, like my threading tool, as I noticed when threading between centers that the QCTP can't get very close on the TS end due to the diameter of the center. My longer ones will allow me to get the QCTP back an inch but still have good support under the tool.
I don't see a reason why they need to be hardened, my self. There is no real wear on them, as they only move loosely on the tool post for 2 inches, and only when you are changing the part.

Chris
 
I bought some 1018 to make some. I want to make some that support more extension of the HSS tools, like my threading tool, as I noticed when threading between centers that the QCTP can't get very close on the TS end due to the diameter of the center. My longer ones will allow me to get the QCTP back an inch but still have good support under the tool.
I don't see a reason why they need to be hardened, my self. There is no real wear on them, as they only move loosely on the tool post for 2 inches, and only when you are changing the part.

Chris
If the 1018 is cold rolled, watch out for warping while machining it. It can be dealt with, but must be kept track of. Hardening metal does not make it stiffer. Hardening does not change the modulus of elasticity of steel, which is resistance to deflection, and all steels have about the same elastic modulus. High alloy steel is not stiffer than mild steel. If you want stiffer, you need to go to a stiffer material, like carbide, or go to a larger cross section. Hardened tool holders only have more resistance to wear and dings. They also can spring out of tolerance when heat treated, so allowance needs to be left for that, and then finish ground after hardening and tempering. All quite doable, but most home shops are not set up for that. I do not think it is worth the effort for shop made holders.
 
I would suggest roughing out the four sides of that block including the slot for the dovetail first. That way, if there is any warpage, it can be removed with finishing passes. I doubt you will get any measurable difference due to warpage in a chunk of steel of that dimension. Once it's chopped up into individual pieces for tool blocks, you're home free! The cold rolled will give you a bit more strength over using hot rolled in the long run, won't wear out as quickly. Ken
 
Based on your comments I'm guessing the purchase has been made and you are making parts.
 
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