What material for a press tool.

[David George 1Participant @davidgeorge1]

I am in the process of making a press tool to emboss the numbers and lines in a brass disk which fitts onto an   M Type lathe. It shows the angle of the compound top slide. The part is a thin brass disk 2 inch diamiter and 0.015 inch thick. The press plate will press the area around the numbersand lines leaving them creating a well for black enamel so the characters stand out. the embossing tool only goes in 0.007 deep.

I was going to make it from gauge plate o1 steel and get it hardened and tempered  but wondered if anyone has worked with press tooling and could suggest a diferent steel which may be more suitable.

David

 

 

 

 

[bernard towersParticipant @bernardtowers37738]

Why not engraving tool and stamping?

[Tony Pratt 1Participant @tonypratt1]

The hundreds of press tools I made were from distant memory predominately O1 steel. Relatively cheap, easy to machine also straightforward to heat treat.

Tony

[Andrew CrowParticipant @andrewcrow91475]

I would agree with Bernard, engraving would be an easier and more accurate option.

Andy

[Peter Cook 6Participant @petercook6]

With numbers that small on brass, I would be tempted to try chemically etching the markings.

[Ian PParticipant @ianp]

I think David wants a die with raised lines and figures so that he can make multiple identical brass disks.

Why else would his picture of the proposed ‘press tool’ have the numerals shown mirrored?

Ian P

[bernard towersParticipant @bernardtowers37738]

How many lathes does he have?

[Wade BeattyParticipant @wadebeatty78296]

Bernard Towers, how did you make those nice numbers on that dail? Very nice.

Wade

[David George 1Participant @davidgeorge1]

Tony Do you have any information on the hardness you used on 01 steel as I have started machining the blanks and arranged for laser cutting of the engaving but I dont want to make it too hard and have it crack or too soft and fail to emboss the brass disk. The die will at the same time cut the outside diamiter, punch the central hole and form two 45 degree pimples for location on countersunk screws.  This is to be used in a fly press.

David

[DC31kParticipant @dc31k]

You omit a crucial piece of information from your initial post: the number of items to be pressed.

If it is one or two-off, the most economic material (and process) will differ to that for a tool needed to produce a run of 10,000 pieces.

The cost of the tool is shared over the number of pieces. Compare spending £10 on something used twice to £100 spent on something used 100 times.

[David George 1Participant @davidgeorge1]

This is the piece which fits on to the compound top slide and this is the proposed tool to press them out.

David

 

[David George 1]

On David George 1 Said:

Tony Do you have any information on the hardness you used on 01 steel as I have started machining the blanks and arranged for laser cutting of the engaving but I dont want to make it too hard and have it crack or too soft and fail to emboss the brass disk. The die will at the same time cut the outside diamiter, punch the central hole and form two 45 degree pimples for location on countersunk screws.  This is to be used in a fly press.

David

David, 60 – 62 Rockwell ‘C’ was the usual specified hardness for press tools.

Tony

[bernard towersParticipant @bernardtowers37738]

Its done with a stamp holding fixture (top quality stamps) and done straight after the line engraving so the work is in the right place. I find that getting the impressions even depth is better done by several light taps and inspect than one big thump as some letters/numbers have more material to move. 1 is minimal compared to 8. And of course the finish with the time honoured fine file covered in oil as GHT recommended.

[Ian PParticipant @ianp]

I’m not familiar with an ‘M’ type lathe but if the plan is to replicate or make an identical copy of the brass plate in your picture then I suggest creating the depression around the test and index lines by etching.

Etching was almost certainly the method by which the original was made.

Ian P

 

 

[HOWARDTParticipant @howardt]

Carrs Toolsteel Technologies in Tipton, if you really want a toolsteel.  Used to deal with them many years ago, tell them what you are making and they will supply the best steel for that purpose and they will provide the size you want.

[Wade BeattyParticipant @wadebeatty78296]

Thank you Bernard T for your reply

 

Wade

[Mick BaileyParticipant @mickbailey28509]

I’m a little late to this thread, but  the disk is a good candidate for etching using the ‘toner transfer’ method that’s mainly used for etching PCBs. I’ve used it frequently for nameplates in brass where I want raised lettering and flood-fill the background with paint. The method has excellent repeatabiliy and the outlines are crisp without undercut.

[David George 1Participant @davidgeorge1]

Die back from hardening and 3D laser engraving.

[DiogenesParticipant @diogenes]

What hardening process did you use in the end, David?

[David George 1Participant @davidgeorge1]

Hi I had it profesionaly hardened and tempered at CBS heat treatment Long Eaton. It was a bit iffy for me to harden as it could become a bit brittle. It was made 50RC which was sugested hard enough for bressing the brass.

David

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