Surface Finish on HRS

[ddickey]

You can get A2, O1, W1, 4140HT and many others as hot rolled.

 

[Forty Niner]

And the answer is... shear tool!!!

View attachment 514897

View attachment 514898

Looks and feels better in real life than even that photo.
@GT-6 Racer - Thanks for this suggestion!

I have also had excellent results using a HSS shear tool. With a very shallow depth of cut and a sharp tool it almost looks ground.

 

[stupoty]

As mentioned above, unless you buy from a known source and spec it out you get what's on top of the pile.

At work we had to stop dealing with one supplier as everything coming in was from china, and had razor sharp burrs, had a greasy black crap on it that would instantly give you rash and......Was total crap to try and work with.

Oh, and it stunk to high heaven, and every stick of that crap was tapered from one end to the other.

Wow , sounds bad, I've had a "bad steel" issue once and it was one piece in a collection of random steel ,but apart from that it has been consistently ok.

Stu

 

[RaisedByWolves]

Wow , sounds bad, I've had a "bad steel" issue once and it was one piece in a collection of random steel ,but apart from that it has been consistently ok.

Stu

If I were the sadistic type I would send you some of the by length aluminum we get in the box stores.

Looks like aluminum, tastes like aluminum, but under its glass hard anodized surface its Wrigley's.

 

[mksj]

Also depends on the type of steel, the 4000 series such as 4130/4140 needs higher feed rates, there are also the factors of the nose radius and DOC. I primarily use CCMT inserts on HR steel, but the inserts are a bit sharper and suitable for both SS and steel, so a bit sharper postive edge profile. Was getting pretty crappy finish in HR 4140 until I increased the feed to 0.010"/R, at lower feeds it just wasn't cutting the metal. On 1018 HR tends to be pretty poor surface finish no mater what, but seem to do fine with HR steel 1045 and 1144, 4000, 8000 series turns nicely if I recall I did a chuck out of 8620. You may also have a rigidity issue, and in that case a sharper positive cutter should help. I tend to use carbide inserts that are also rated for SS/exotic metals due to the edge profile/positive rake, unless you are dealing with hardened steels. One needs to cut the metal as opposed to push and tear it.

HR 4140, initial feed rate was around 0.004"/R, then midway increased to 0.010"/R, Iscar CCMT 32.51 IC907 insert.

 

[stupoty]

If I were the sadistic type I would send you some of the by length aluminum we get in the box stores.

Looks like aluminum, tastes like aluminum, but under its glass hard anodized surface its Wrigley's.

We do get box store aluminum in the uk , the only saving grace of it is it's about 20x over priced so you don't get tempted

Stu

 

[rwm]

I believe this material is 1018 or 1045HR. I initially used a CCGT roughing cutter and then went to a CCGT with a ground edge and very small nose radius. I tried multiple feeds and speeds without success. I then tried HSS with a shallow rake followed by a high rake cutter for aluminum. No dice.
The shear tool worked perfectly from the start.

 

[ChazzC]

If I were the sadistic type I would send you some of the by length aluminum we get in the box stores.

Looks like aluminum, tastes like aluminum, but under its glass hard anodized surface its Wrigley's.

Most box-store shapes are 6063, which can be gummy; unfortunately, due to the manufacturing process, some sizes of angle/channel are only available in 6063. I got around this for a recent project by starting with square tube (I also wanted square inside corners which weren't easy to find in channels):

 

[rwm]

You can get A2, O1, W1, 4140HT and many others as hot rolled.

Yes- I guess I should have been more specific in my initial post. This is some kind of cheap mild steel that was likely purchased as a single stick and cut into 10" lengths. It has the typical gray mill scale. It cuts super easy on a bandsaw.