Mold & Die cutting tools
Cavities and cores in hardened tool steel punish tooling: heat, abrasion, and the surface-finish bar that decides how many hours of hand polishing follow. RobbJack's DM/MDM die-mold line was built for hard milling — and our Crystallume diamond coatings own the graphite electrode side of the shop.
The challenges — and how we cut them
1Hard milling to 70 HRc without babying the tool
Tested in D2 at 58 HRc, the DM/MDM end mill lasted 450% longer with 909% less wear than comparable hard-milling tools — and it's capable to 70 HRc, cutting dry. AlTiN coating holds its hardness to roughly 1,470°F, which is why it (not TiCN, good to ~750°F) belongs on hardened work.
2Graphite electrodes wear carbide out in minutes
Diamond-coated tools run 10 to 30 times longer than uncoated carbide in graphite — RobbJack's Crystallume CVD diamond coating is grown in-house, on tools ground in the same building.
3Deep cavities, draft, and reach
Necked and tapered geometries reach deep features without sacrificing core strength, and long-reach ball nose tools in the DM line keep finishing predictable at depth. When a standard doesn't reach, a special is a quote away.
The mold & die toolset
DM / MDM
Die-Mold Ball End Mills
Hard milling to 70 HRc dry — 450% longer life, 909% less wear in D2 at 58 HRc.
ExploreDCC
Diamond-Coated Graphite Tools
Crystallume CVD diamond — 10–30× the life of uncoated carbide in graphite.
ExploreSpecials
Tapered & Necked Specials
Draft angles, deep reach, and custom geometry — quoted from your print.
ExploreThe proof — documented results
- 450%
- longer life — DM/MDM in D2 at 58 HRc
- 70 HRc
- hardness capability, dry cutting
- 10–30×
- tool life — diamond coating in graphite
Mold & Die machining questions
What end mill can actually cut 60+ HRc tool steel?
RobbJack's DM/MDM die-mold series — tested in D2 at 58 HRc it lasted 450% longer with 909% less wear than comparable tools, and it's rated to 70 HRc cutting dry. Use AlTiN coating for hardened work; it stays hard to about 1,470°F.
What's the right tool for graphite electrodes?
Diamond-coated carbide — in graphite it runs 10 to 30 times longer than uncoated. RobbJack's Crystallume CVD diamond coating is applied in-house on our own tools.
Can I get draft angle or extra reach on a standard tool?
Yes — tapered, necked, and reach-modified versions of standards are everyday specials. Start from the closest standard on the special-tool quote and application engineering takes it from there.
From the machining lab & case files
Put it on your machine
Send us your toughest mold & die part. Application engineering will spec the tool and the numbers — or quote a special from your print.