How to clean/polish threaded steel after heat-treatment?

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keithfrancis

Plastic

Joined

Mar 13, 2019

• Mar 13, 2019

• #1

Hi everyone, I'm new here. Forgive me if this is a basic question but I can't seem to find an answer over the internet.

Anyway, we heat-treated a tool steel. this said tool steel is threaded. now how can I polish the thread without it having to look like burnt charcoal? We tried to polish it directly but the sharpness of the thread decreased.

thanks in advance!

 

Ember

Aluminum

Joined

Feb 28, 2019

• Mar 13, 2019

• #2

It depends on what the part is, the tolerances and it's size. If the thread is on a shaft and needs to be a tight fit you might be better off leaving the blackened finish, any shaft I make will have the faces ground after hardening and any threads will be left blackened. If the tolerance isn't to high you should be OK polishing, if the threads are a fine pitch use a nut that fit's the thread and some very fine lapping paste, you won't be able to get it shiny but you should be able to remove any roughness from the hardening process

 

R

Red James

Stainless

Joined

Jan 26, 2013

Location

Plainfield, Indiana, USA

• Mar 13, 2019

• #3

For parts that need to be "clean" find a heat treater with vacuum equipment. No clean up needed.

 

R

RJT

Titanium

Joined

Aug 24, 2006

Location

greensboro,northcarolina

• Mar 13, 2019

• #4

I second the vacuum heat treating, but to clean up what you have a stiff wire brush either hand held or on a bench grinder and some elbow grease.

 

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Larry Dickman

Titanium

Joined

Jan 30, 2014

Location

Temecula, Ca

• Mar 13, 2019

• #5

we use a red wheel, ie a buffing wheel made from red scotch brite pads cut into a circle. works great

 

K

keithfrancis

Plastic

Joined

Mar 13, 2019

• Mar 20, 2019

• #6

Larry Dickman said:

we use a red wheel, ie a buffing wheel made from red scotch brite pads cut into a circle. works great

Click to expand...

similar to a non-woven finishing wheel?

 

K

keithfrancis

Plastic

Joined

Mar 13, 2019

• Mar 20, 2019

• #7

RJT said:

I second the vacuum heat treating, but to clean up what you have a stiff wire brush either hand held or on a bench grinder and some elbow grease.

Click to expand...

thanks for the suggestion. a vacuum heat treat furnace would surely be costly, maybe in the future. as for the wire brush, will try this on the next batch.

 

L

Larry Dickman

Titanium

Joined

Jan 30, 2014

Location

Temecula, Ca

• Mar 20, 2019

• #8

keithfrancis said:

similar to a non-woven finishing wheel?

Click to expand...

ya. it's flexible enough to get into all the nooks and crannys, fine enough not to alter any surfaces. gets all the neat treat muck off and leaves the part nice and shiny.

If you get a quote for vacuum heat treating, make sure you're sitting down.

 

D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Mar 20, 2019

• #9

keithfrancis said:

thanks for the suggestion. a vacuum heat treat furnace would surely be costly, maybe in the future. as for the wire brush, will try this on the next batch.

Click to expand...

What's wrong with the stainless steel pouches ?

 

S

Shawnrs

Stainless

Joined

Mar 30, 2016

• Mar 20, 2019

• #10

Has anyone tried tapping the parts after heat treatment? On our shaft line we tape everything after heat treatment.

 

dgfoster

Diamond

Joined

Jun 14, 2008

Location

Bellingham, WA

• Mar 20, 2019

• #11

digger doug said:

What's wrong with the stainless steel pouches ?

Click to expand...

Or to put it another way:
OP, did you use stainless pouches with a bit of paper inside each carefully crimped pouch?

Also, a pic of the treated part or, if you can’t rrlease a part photo, a portion of the part would allow folks here to comment if you are getting expected discoloration or more than normal.

Denis

 

5

5 axis Fidia guy

Stainless

Joined

Aug 17, 2006

Location

Wisconsin

• Mar 20, 2019

• #12

If you need really nice threads, when it's all said and done, your better off thread milling them after heat treatment.

 

michiganbuck

Diamond

Joined

Jun 28, 2012

Location

Mt Clemens, Michigan 48035

• Mar 20, 2019

• #13

Making cutting tools years back at CutMore Tool we would figure the material expansion or shrink them order special over or under size taps. Then after heat treat we would re-tap the threads with a standard tap so the customer could gauge to be proper fit.

Some fussy customers would go/no go threads.

Yes this mostly for brazed TCT cutting tools.

 

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lethal375

Aluminum

Joined

Oct 16, 2017

• Dec 27, 2019

• #14

dgfoster said:

Or to put it another way:
OP, did you use stainless pouches with a bit of paper inside each carefully crimped pouch?

Also, a pic of the treated part or, if you can’t rrlease a part photo, a portion of the part would allow folks here to comment if you are getting expected discoloration or more than normal.

Denis

Click to expand...

I just found this post and also have the same problem

My parts are A311 and require oil quench so cleaning after HT is a time consuming job!
Thought about bead blasting?
Wire wheel leaves a polished dark surface

Anyone try a Nylon bristle abrasive impregnated wheel to clean down in threads?