LH High-Hardness End Mill for 60HRC+ Steel | PST Coated Carbide-Win Win Industrial Co., Ltd

Highlights

Key Advantages

PST coating hits Hv 3600 — that's the wear resistance layer doing the heavy lifting when you're cutting 60HRC+ steel at production rates.
Covered steel grades include S136, 8407, H13, SKS, SKH51 and DC53 up to roughly 65HRC, so mold shops can standardize on one series across most hard-milling jobs.
Roughing and finishing in the same setup. The high-rigidity body and chip flute design keep deflection down so you're not babysitting the cut.
Si element in the coating adds abrasion resistance — translates to more parts per tool and fewer mid-job replacements.
Square, corner radius and ball nose in standard and long lengths: 26 + 21 + 37 specs, φ1–20mm range, so odd pocket depths don't force a custom order.
Friction coefficient μ 0.25–0.35 and film thickness 1.5–2.5 μm — numbers that mean less heat at the edge and predictable coating life.

Use Cases

Applications

Mold industry hard milling — cores, cavities and inserts in 60HRC+ steel where chip evacuation and tool rigidity decide the finish.
Quenched and tempered steel (NAK55, NAK80, HPM1) around 45HRC — roughing pockets and finishing walls without switching to a separate finishing tool.
High-hardness grades S136, 8407, H13, SKS, SKH51, DC53 up to ~65HRC — the daily diet for this cutter.
Stainless steel SUS303 and SUS304 up to ~35HRC — light finishing and slotting where galling is a concern.
Ordinary steel S45C–S55C, SS400, SCM up to ~39HRC — general milling when the job doesn't justify a dedicated hard-milling tool.
Long-reach jobs using the long-type square, radius or ball nose variants — deep cavities and ribs where standard length won't reach.

Specs

Technical Specifications

Series Name	LH
Composition Code	PST
Coating Color	Copper Brown
Surface Hardness	Hv 3600
Vaporization Start Temperature	1200 ℃
Standard Film Thickness	1.5~2.5 μm
Friction Coefficient	μ 0.25~0.35
Suitable Workpiece Materials	Quenched and Tempered Steel (~45HRC), High-Hardness Steel (~65HRC)
Square End Type	φ1~20mm \| Standard / Long Type, 26 specifications
Corner Radius Type	φ3~16mm \| Standard / Long Type, 21 specifications
Ball Nose Type	R1.5~R10mm \| Standard / Long Type, 37 specifications

Details

Detailed Description

"Chinese slogan: Machining workpieces of 60HRC and above, high durability, high cost performance!
Coating Parameter Table
Table
Item Parameter
Series Name LH
Composition Code PST
Color Copper Brown
Surface Hardness Hv 3600
Vaporization Start Temperature 1200 ℃
Standard Film Thickness 1.5~2.5 μm
Friction Coefficient μ 0.25~0.35
Suitable Workpiece Materials Quenched and Tempered Steel (~45HRC), High-Hardness Steel (~65HRC)
✅ Machinable Material Details
Ordinary Steel (S45C~S55C,SS400,SCM) ~39HRC
Quenched and Tempered Steel (NAK55,NAK80,HPM1) ~45HRC
High-Hardness Steel (S136,8407,H13,SKS,SKH51,DC53): ~52HRC / ~54HRC / ~65HRC
Stainless Steel (SUS303,SUS304) ~35HRC
Not Mainly Targeted: Cast Iron, Aluminum Alloy, Titanium Alloy, Copper Alloy, Graphite, Resin
Product Design Features
Adopts high-rigidity structure + unique chip flute design, contains Si element coating, with extremely high wear resistance.
Machining Scenarios
Stable cutting in both roughing and finishing; excellent wear resistance for long tool life machining.
Applicable Industries
Mold Industry
Specification Range
Square End Type: φ1~20mm | Standard Type / Long Type, 26 specifications
Corner Radius Type: φ3~16mm | Standard Type / Long Type, 21 specifications
Ball Nose Type: R1.5~R10mm | Standard Type / Long Type, 37 specifications"

FAQ

What hardness can this end mill actually handle?

It's built around 60HRC and above — that's the design target. In practice, customers also run it on quenched and tempered steel around 45HRC and on S136, DC53 and similar grades up to about 65HRC. Stainless up to 35HRC works too. If your workpiece is softer than that, you're probably paying for hardness you don't need — a general-purpose cutter may be the better cost call.

Which materials should I keep this tool away from?

Cast iron, aluminum alloy, titanium alloy, copper alloy, graphite and resin are not the target here. The coating and flute geometry are optimized for hard steel, so running aluminum or graphite will give you poor chip evacuation and short tool life. Pick a series matched to those materials instead.

What's the story with the PST coating?

Copper-brown PST, Hv 3600 surface hardness, film thickness 1.5–2.5 μm, friction coefficient μ 0.25–0.35, and it starts vaporizing around 1200℃. The Si element is what gives it abrasion resistance in hardened steel. Practically: less heat at the cutting edge, slower wear, and you're not changing tools as often.

Can I really use one tool for both roughing and finishing?

Yes — that's the point of the high-rigidity body and chip flute design. You can rough out a pocket and come back for the finish pass without pulling the tool. That said, if your finish tolerance is tight, a dedicated finishing pass with a fresh edge still gives you the best surface. The LH just means you don't have to stop and re-tool between operations.

What sizes are available?

Square end: φ1–20mm, standard and long, 26 specs. Corner radius: φ3–16mm, standard and long, 21 specs. Ball nose: R1.5–R10mm, standard and long, 37 specs. If you're running deep cavities, the long types are worth a look — they save you from ordering custom lengths.

How do I make sure I'm ordering the right spec?

Send us your workpiece material and hardness, depth of cut, spindle speed and machine type. We'll confirm the recommended model, coating option and delivery schedule. If you're between two specs, tell us the application — that's usually enough to pick the right one.