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will spring steel mill?

Posted: Wed Jan 31, 2018 5:29 pm
by michaellynn2
Hello Everyone, I now know where to buy my spring strips. Can a carbide cutter mill a slot instead of punching the slot? I do not want to anneal the springs only to need to heat treat them. What are my options?

Re: will spring steel mill?

Posted: Wed Jan 31, 2018 5:43 pm
by southwestern737
Yes it will, I drilled and slotted mine with carbide drill and mill. Works best if you stack them and clamp them tight.

Re: will spring steel mill?

Posted: Wed Jan 31, 2018 7:51 pm
by jscarmozza
My two cents. I made 20 leaf springs from 3/16" wide x 0.032" thick blue spring steel. I had bad luck trying to drill the center hole for the 0x80 screw used to hold the stack of leafs together. I wound up punching the holes, which worked well. That being said, in a previous discussion of this matter, Bill Shields said that punching spring steel will likely result in micro-fractures which will sooner or later result in the leafs breaking at the punch hole. My project hasn't been put into service so I can't confirm that my springs will hold up or not. And, if you need slots, I can't see any other way of making them other than by milling, but I can tell you that carbide drills get expensive and break easily; make sure the gang of leafs you are going to work on is well secured...any movement and you'll break the drill or end mill cutter. John

Re: will spring steel mill?

Posted: Wed Jan 31, 2018 9:25 pm
by daves1459
As mentioned above blue tempered spring steel can be milled with carbide cutters. Lacking a carbide center drill and carbide drills alone tended to wonder at the tip so I used a two fluted center cutting end mill to make the pilot hole. I found that side milling was very tough and hard on the cutter so resorted to plunging the mill up and down and found .020" steps worked well. I also found that rotating the end mill the same rpm as for a high speed steel end mill in low carbon steel gave good cutter life. The plunge cutting leaves a rough edge in the slot. Once the slot was cut to length I placed the end mill in one end of the slot then side milled the length of the slot with a .005" offset on both side of the slot. In my case my hangers were .125 thick X .500 wide for 1.5 inch scale. I found widening the slot .010" to .015" and lengthening the slot .030" over the width of the hanger to the centerline of the end mill allowed for good articulation of the hangers in the slots.

Re: will spring steel mill?

Posted: Wed Jan 31, 2018 9:45 pm
by Bill Shields
keep in mind that the one thing that will destroy a carbide end mill is chatter.

when you use one to make holes in this stuff, you must keep everything down SOLID...or you will be 3-4 holes into it and have a gone end mill.

ball end mills are great for starting holes...

Re: will spring steel mill?

Posted: Wed Jan 31, 2018 9:52 pm
by michaellynn2
Do I keep constant pressure until that end mill cuts the spring materail

Re: will spring steel mill?

Posted: Wed Jan 31, 2018 10:02 pm
by michaellynn2
Would it help to skin the bark off the material with small dermal wheel to remove the surface or is it hard all the way through. I am very new at this. I do not want to eat up end mills in my learning curve.

Re: will spring steel mill?

Posted: Thu Feb 01, 2018 1:00 am
by Dick_Morris
spring material is hard all the way through. Case hardening is the typical process that just hardens the outer surface of mild steel and leaves the inside soft.

I found some carbide spade drills that are made for drilling hard material. I bought them specifically for the springs and have only used them a little bit, but so far they seem to work. I bought the hand punch that is suggested for punching springs (don't remember the brand) and the punch head failed in short order. That's when I got the drill bits.

Re: will spring steel mill?

Posted: Thu Feb 01, 2018 2:30 am
by EOsteam
Here is a link to a previous post of mine with 1095 spring steel and the need to reduce the width from 1" to 7/8".

viewtopic.php?f=4&t=105037&p=371523#p371523

HJ

Re: will spring steel mill?

Posted: Thu Feb 01, 2018 8:03 am
by Bill Shields
yes on the constant pressure, or the tool will chip.

Re: will spring steel mill?

Posted: Thu Feb 01, 2018 3:24 pm
by Kimball McGinley
I recall reading some expert (maybe Don Young, Greely or LBSC Lawrence) that said you can get away with hard strips with soft ends. He softened them by sticking them through a potato, leaving just the end to be annealed. He then torch heated them red and done. They could now be worked with HS Steel tools. Don't recall about a center hole though.
I also have not done this...

Re: will spring steel mill?

Posted: Thu Feb 01, 2018 5:56 pm
by Bill Shields
when you are done you can put ketchup on the potatoes and have them with a burger.

yes, this will work...you can also tightly clamp the spring with a machinist's clamp...

but as you say, doesn't solve the 'hole in the middle' problem.

OR if you are really resourceful, you can find someone with a laser and have them punch holes, cut to length and make grooves in the end...but then where is the fun in that?