Most shops lose 30–50 % tool life on steel roughing simply because they use the wrong coating for the hardness. We run GM, PM and HM series every day. Here’s exactly which one wins for your job — based on real cutting data, not theory.
Every week we get the same call from machinists: “My roughing end mills are dying too fast on this steel part — which coating should I run?” The answer is straightforward once you know the workpiece hardness. After thousands of hours on carbon steel, alloy steel, P20, 718, H13 and D2, we’ve settled on three clear winners from our own lineup.
HRC ≤40 (45# carbon, low-alloy steel) → GM Series + TiSiN: best wear resistance and price/performance
HRC 40–55 (P20, 718, pre-hardened mold steel) → PM Series + AlTiCrN Composite: superior heat and edge strength
HRC 55–68 (H13, D2, SKD61 tool steel) → HM Series + Balzers DR: extreme heat protection and anti-chipping
70 % of everyday steel roughing jobs fall into the first two series. HM is the specialist when the part really gets hard.
Coating Comparison Table by Hardness
Why each coating wins (or fails) on the shop floor
Real case studies with actual tool-life numbers
30-second selection checklist
Recommended Amony GM/PM/HM roughing end mills
Frequently Asked Questions
| Workpiece Hardness | Recommended Series | Coating | Key Advantage | Typical Tool Life Gain* | Best Applications |
|---|---|---|---|---|---|
| HRC ≤40 | GM Series | TiSiN | Excellent abrasion resistance + anti-adhesion, lowest cost | 1.8–2.5× vs standard TiAlN | 45# carbon steel, low-alloy steel, high-volume roughing |
| HRC 40–55 | PM Series | AlTiCrN Composite | Superior oxidation resistance, higher edge toughness at elevated temps | 1.8–2.2× | P20, 718, pre-hardened mold steel, alloy steel |
| HRC 55–68 | HM Series | Balzers DR | Extreme heat resistance + anti-chipping, survives dry/MQL | 2.5–3×+ | H13, D2, SKD61 high-hardness tool steel |
*Compared with standard TiAlN coating under identical parameters on the same machines. Data from our production floor and customer feedback.
TiSiN on the GM Series forms a stable oxide layer that fights abrasion. We routinely run 4-flute roughers on 45# steel at Vc 180 m/min and fz 0.12 mm/tooth. Tool life jumps from 22 minutes (standard TiAlN) to 58 minutes with almost no coating delamination.
Once temperature climbs, AlTiCrN Composite on the PM Series takes over. The chromium addition keeps the coating hard and tough above 550 °C. On 718 mold steel we increased feed 25 % and still doubled tool life versus older tools.
Only Balzers DR on the HM Series survives the 900 °C+ cutting zone. In a recent H13 dry-cavity job the previous tool chipped after 11 minutes. The HM Series with Balzers DR ran 34 minutes with only light corner rounding.
Customer was changing standard TiAlN tools every 22 minutes. Switched to GM Series 4-flute roughing end mill with TiSiN coating. Same parameters → 58 minutes per edge. No coating peeling, just steady flank wear.
PM Series AlTiCrN Composite 6-flute rougher replaced competitor tool. Feed increased 25 %, tool life went from 19 minutes to 47 minutes per edge. Interrupted cuts no longer destroyed the edge.
HM Series with Balzers DR ran dry on a deep cavity. Previous tool lasted 11 minutes before chipping. HM Series cleared 34 minutes per edge. Customer completed the entire mold cavity in one tool.
Keep this on your phone or print it. Answer the questions and you’ll know exactly which Amony roughing end mill to grab.
Workpiece ≤40 HRC and you want the lowest cost per edge? → GM Series + TiSiN
40–55 HRC, mold steel or alloy steel? → PM Series + AlTiCrN Composite
55–68 HRC, high-hardness tool steel? → HM Series + Balzers DR
Dry machining or MQL? → HM Series with Balzers DR
Maximum metal removal rate needed? → PM or HM 6-flute roughers
Ball-nose for 3D roughing? → All three series have ball-nose versions – just match coating to hardness
TiSiN coated, HRC≤40 steel. The everyday workhorse for carbon and low-alloy roughing – highest metal removal rate at the lowest cost.
View GM SeriesAlTiCrN Composite coating, HRC≤55. Perfect balance of toughness and heat resistance for P20, 718 and alloy steels.
View PM SeriesBalzers DR coating, HRC55-68. Built for hardened tool steels – survives dry and high-temperature conditions.
View HM SeriesSend us the material grade, hardness, machine model and current tool life. Our engineer will reply with the exact series, flute count, coating and cutting parameters — no charge.
Get Free RecommendationSteel roughing is 90 % about matching the coating to the hardness: GM Series TiSiN for everyday carbon steel, PM Series AlTiCrN Composite for mid-hard mold steels, and HM Series Balzers DR when the part is truly hard. Get this right and you’ll double tool life, cut tool changes in half, and lower cost per part immediately.
Ready to test the right tool on your machine? Browse the full GM/PM/HM range or send us your material and hardness — we’ll give you the exact recommendation within hours.
Contact our experts today for a free quote or technical consultation.