Hardmillers

[88Matt]

Got a steel rule die to make with a knife edge along the contour. I would like to hardmill the outside angle and then wire the inside. I need a material around 48-52c preferably. The smallest endmill I'll use is a .030in ball. This will be cut on a VMC 50 taper with 8k spindle.

 

I need some opinions and recommendations on materials and tools.

 

 

We are looking at something like 13-8PH or VascoMax C-250. I am really liking the VascoMax but it is hard to come by I am being told by my estimator.

 

Thanks

[[email protected]]

I would use A-2 or D-2 and 8000 rpm is not near enough speed for a .03 tool

 

I use Fraisa tools for hardmilling

http://www.fraisausa.com

 

HTH

[88Matt]

A2 is no good, to brittle. We might try D2. It is used on a clicker press and the knife edge doesn't hold up.

 

I should hear if I can get the VascoMax today. If so that is what they want to go with.

 

quote:

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8000 rpm is not near enough speed for a .03 tool

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I was afraid of that.

 

Any other suggestions would be welcome.

 

Thanks

[Odell]

You should use S-7 for this app. and the tool you could use for hard machining this Mtrl. is an Exocarb-SHP 4010 from OSG. I only have 10,000 rpm. and i get away with about a .0015" / .0018" chip load.

[Dave.L]

quote:

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You should use S-7 for this app

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S7 sounds like the best choice since it's a shock tool steel. Hammers and such are made from this.

 

Like all tool steels, they are designed to be very hard, around 58-62 Rc.

 

People think they can heat treat A2 to 45 Rc so it won't be as brittle, but then you are not using the steel as it was intended. If you want a lower Rc, use something like 4140 but the performance will be totally different to a tool steel.

 

HTH.

[moeh]

I have made many punches and dies with A2. As long as it is heat treated corectly, Rc 55-57, I have never had problems with it being to brittle. D2 is more prone to being brittle than A2. For the applications I have tried S7 on, it has not performed better than A2.

[moeh]

Thinking about it, the times when A2 has not worked well, I have had good results with M2.

[Dave.L]

quote:

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D2 is more prone to being brittle than A2

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With all due respect, that statement is not true. As I design engineer for almost 20 years, D2 is far better for punches than A2, it holds it's edge much better.

 

A2 is a excellent tool steel for many wear related components, components that don't see a shock load.

[JAMMAN]

+1 for D2 though it can be a pain to grind. Stable to the bone.

[FLHX95ci]

About 80% of our work is hardmilling in Ramax, Mirrax, S-7, A2 and D2. S-7 would be the best bet IMO.

 

As far as tooling, we have tried ALLOT of brands (Haneda, Frasia, SGS, ISI, Union Tool, etc...) and we have the best bet with Seco/Jabra endmills.

 

For a .030 ball, try Seco's "113" series ballnose, we would use the Seco# 113ML008TN (.8mm ball), with only 8000 RPM though you will be down in the 12-13IMP for finishing though.

[88Matt]

They decided to go with 13-8ph @ R48.

 

Engineer wants me to go with carboloy, kennametal, or robbjack; but will look at any cutter. needing both an inserted em to rough and solid em's to finish. smallest em will be a .032Ø. Problem is still not enough rpm with what I have seen (8k). Any more suggestions would be helpful. Thanks

[mold100]

M-2, or M-4 FROM CARPENTER......... ?

[Kevangel]

Description

PH 13-8 Mo* stainless is a martensitic precipitation/age-hardening stainless steel capable of high strength and hardness along with good levels of resistance to both general corrosion and stress-corrosion cracking. In addition, the alloy exhibits good ductility and toughness in large sections in both the longitudinal and transverse directions. The excellent properties of PH 13-8 Mo stainless are obtained through close control of chemical composition and microstructure plus specialized melting which reduces impurities and minimizes segregation. Compared to other ferrous-based materials, this alloy offers a high level of useful mechanical properties under severe environmental conditions.

13-8 Mo stainless has good fabrication characteristics and can be age-hardened by a single low temperature treatment. Cold work prior to aging increases the aging, especially for lower aging tempratures.

13-8 Mo stainless has been used for valve parts, fittings, cold-headed and machined fasteners, shafts, landing gear parts, pins, lockwashers, aircraft components, nuclear reactor components and petrochemical applications requiring resistance to stress-corrosion cracking. Generally, this alloy should be considered where high strength, toughness, corrosion resistance, and resistance to stress-corrosion cracking are required in a steel showing minimal directionality in properties.

*PH 13-8 Mo stainless is a registered trademark of Armco Inc.

 

Seems like a strange choice. I doubt if you could go wrong with D2...profoundly tough and abrasive resistant. Try grinding some compared to A2 or S7. S7 really shines in fragile "pass cores" on molds that might be flexing a bit when mold closes and it shuts off plastic in an area of part to core out an opening , but is dirty to weld for repair.

[88Matt]

The material is already decided on. I am needing to order some endmills to it at the R48 level with a 8k spindle. Any recommendations?

[Chipmakr]

If they want you to use SECO go with the Jabro brand since they are now a part of SECO. Call Eric or JL up in VA @ 1-877-908-3726. Those boys will be able to tell you how to get what you need out of the 8K.

[DavidSV]

Why do you have to go with SECO instead of choosing the best tool? Sounds like someone is getting a cut of that action

[Fred @ Slate Industries]

Good to Best:

O-1

A-2

D-2

M-2 / M-4

Cpm 10 v

T-15

Carbide.