APMT 1135 for Stainless Steel Milling: Complete Buyer's Guide (2026)
The APMT 1135 PDR is the small-diameter face milling insert of choice for stainless steel 304 / 316 / 17-4 PH. This guide covers the 11 mm IC insert geometry, grade selection (Korloy KF5900 / PC5300, Mitsubishi US7020, Sandvik GC2025, ZCC·CT), cutting parameters for stainless + steel + cast iron, and 8-brand alternatives.
What is APMT 1135? (ISO Code Breakdown)
The APMT 1135 insert follows the ISO 1832 standard. Each letter and number tells you about geometry, tolerance, and features:
| Position | Code | Meaning |
|---|---|---|
| 1 | A | Insert shape: A = 85° parallelogram with hole + 0° clearance |
| 2 | P | Relief angle: P = 11° (positive rake face mill insert) |
| 3 | M | Tolerance class: M = ±0.005" thickness, ±0.001" IC (precision) |
| 4-5 | T | Insert type: T = 3/16" thickness (4.76 mm) |
| 6 | 11 | Cutting edge length: 11 mm IC (nominal) |
| 7 | 35 | Corner radius / nose: 3.5 mm (.138") |
| Suffix | PDR / PMR / PDER-Q / PDR-K | Chipbreaker geometry + hand |
For complete ISO 1832 letter-by-letter breakdown of every position, see our Carbide Inserts by ISO Code hub.
APMT 1135 Chipbreaker Selection (PDR vs PMR vs PDR-K)
The chipbreaker suffix on APMT 1135 controls chip control, cutting force, and surface finish. Choosing the right chipbreaker is as important as choosing the right grade:
| Chipbreaker | Best For | Cutting Force | Surface Finish | Coolant Need |
|---|---|---|---|---|
| PDR (Positive Double-sided Roughing) | Stainless roughing to medium | Medium | Ra 1.6-3.2 µm | HP 50+ bar preferred |
| PDR-K (PDR with sharp K-edge) | Stainless finishing, sharp刃口 | Low | Ra 0.8-1.6 µm (best) | HP 70+ bar mandatory |
| PMR (Positive Medium Roughing) | Steel medium, stainless medium | Medium-high | Ra 1.6-3.2 µm | HP 50+ bar preferred |
| PDER-Q (PDR Enhanced Roughing, Q = high-feed) | High-feed face milling | Medium | Ra 1.6-3.2 µm | HP 50+ bar |
| No chipbreaker (flat top) | Cast iron, aluminum | Low | Variable | Dry or flood |
APMT 1135 Grade Selection by Workpiece Material
| Workpiece Material | ISO Class | Recommended Grade | Chipbreaker | Vc Range |
|---|---|---|---|---|
| Carbon Steel (1018, 1045) | P10-P25 | CVD: NC3020, GC4325, US7020 | PMR | 180-250 m/min |
| Alloy Steel (4140, 4340) | P20-P35 | CVD: NC3020, GC4325 | PMR / PDR | 150-220 m/min |
| Stainless 304 / 316 | M15-M25 | PVD: KF5900, PC5300, GC2025, YBM151 | PDR-K (finish) / PDR (medium) | 100-180 m/min |
| Stainless 17-4 PH | M20-M30 | PVD: KF5900, MP8015, TT9080 | PDR-K | 70-120 m/min |
| Duplex 2205 | M25-M35 | PVD: MP8015, TT9080 | PDR-K | 60-100 m/min |
| Cast Iron (GG25, GGG60) | K10-K25 | CVD: PC6510, GC4325, WPP10S | Flat top / PMR | 150-250 m/min |
| Aluminum (6061, 7075) | N10-N25 | Uncoated polished K10 or DLC | PDR-K (sharp) | 300-600 m/min |
| HRSA Inconel 718 | S15-S25 | PVD: MP8015, TT9080, VP15TF | PDR-K | 30-50 m/min |
Browse our full Korloy APMT 1135 inventory (KF5900 stainless grade + PC6510 cast iron grade) or use the Mitsubishi Equivalent Finder for cross-brand alternatives.
8-Brand APMT 1135 Grade Comparison
Every top brand offers APMT 1135 in PVD grade for stainless. Here is the flagship comparison:
| Brand | PVD Grade for Stainless | CVD Grade for Steel | PVD Grade for HRSA | Stock Status |
|---|---|---|---|---|
| Korloy | KF5900 / PC5300 | NC3020 | — (use MP8015) | Wide stock (APKT/APMT) |
| Mitsubishi | VP15TF (APMT1135PDER-H2) | US7020 | MP8015 | Wide stock (APX3000 system) |
| Sandvik | GC2025 / GC2030 | GC4325 | GC1105 | Wide stock |
| TaeguTec | TT9080 | TT8020 | TT9080 | Moderate |
| Sumitomo | AC630M | YBC151 | — | Moderate |
| Iscar | IC807 | IC8150 | IC806 | Moderate |
| Walter | WPP05S | WPP10S | WSP45S | Limited |
| ZCC·CT | YBM151 / YBG2020 | YBC151 | — | Moderate |
For complete 8-brand cross-reference (which grade is equivalent to which), see our Grade Cross-Reference Hub with 4 tier cross-reference tables.
Cutting Parameters for APMT 1135
| Material + Grade | Vc (m/min) | fz (mm/tooth) | ap (mm) | ae (mm) |
|---|---|---|---|---|
| 304 / 316 Stainless + KF5900 (PDR-K) | 100-180 | 0.10-0.20 | 0.5-2.0 | 40-55 mm |
| 17-4 PH Stainless + KF5900 (PDR-K) | 70-120 | 0.08-0.15 | 0.3-1.5 | 40-55 mm |
| 1045 Steel + NC3020 (PMR) | 180-250 | 0.15-0.25 | 1.0-3.0 | 40-55 mm |
| 4140 Alloy Steel + NC3020 (PMR) | 150-220 | 0.12-0.22 | 1.0-2.5 | 40-55 mm |
| Cast Iron GG25 + PC6510 (Flat top) | 150-250 | 0.15-0.30 | 1.0-4.0 | 40-60 mm |
| Aluminum 6061 + Uncoated (PDR-K) | 300-600 | 0.10-0.25 | 0.5-3.0 | 40-60 mm |
| Inconel 718 + MP8015 (PDR-K) | 30-50 | 0.08-0.15 | 0.3-1.5 | 40-50 mm |
For complete material-specific parameter tables and a free calculator, see our Speeds & Feeds Hub.
Common Failure Modes and Quick Fixes
| Failure | Symptom | Likely Cause | Fix |
|---|---|---|---|
| Built-up edge on stainless | Torn surface, weld marks on 304 | Wrong grade (CVD on stainless) or low Vc | Switch to KF5900 PVD; increase Vc 20% |
| Chatter marks | Regular ridges on face | ae too high; cutter rigidity issue | Reduce ae to 40 mm; check shim seating |
| Premature crater wear on stainless | Top surface wears fast, edge fails | Vc too high for PVD coating | Reduce Vc 15%; switch to harder PVD grade |
| Plastic deformation on steel | Edge deforms at high temp | Vc too high for grade; insufficient coolant | Reduce Vc 20%; switch to CVD grade (NC3020) |
| Insert chipping on cast iron | Corner chips on intermittent contact | PC6510 grade mismatch | Switch to tougher grade (WPP10S or IC8150) |
| Chip jamming in flute | Chips pack, insert breaks | Chipbreaker wrong for chip shape | Switch from PDR to PMR (heavier chip) |
Migration Cheat Sheet: APMT 1135 → APMT 1604 and APMT 0602
When to step up or down in APMT 1135 family:
| If You're Using | Switch To | When |
|---|---|---|
| APMT 1135 PDR-K | APMT 0602 PDR-K | Face mill diameter < 50 mm (small cutter) |
| APMT 1135 PMR | APMT 1604 PMR | Face mill diameter > 100 mm (large cutter, higher productivity) |
| APMT 1135 KF5900 | APMT 1604 KF5900 | Larger diameter same grade (most brands offer APMT 1604 in same grade) |
| APMT 1135 PDER-Q (high feed) | APMT 1604 PDER-Q | Larger diameter, same high-feed chipbreaker |
FAQ — APMT 1135 for Stainless Steel Milling
1. What's the difference between APMT 1135 PDR and PDR-K?
PDR is the standard positive double-sided roughing chipbreaker — designed for medium-roughing on stainless and steel at ap 1.0-3.0 mm. PDR-K has a sharper K-edge land for finishing at ap 0.3-1.0 mm where PDR leaves wavy surface. For stainless finishing below 1.0 mm depth, always use PDR-K.
2. Can I use APMT 1135 with CVD grade on stainless?
You can, but it's not optimal. CVD grades (NC3020, GC4325) have rounded edges that don't shear stainless chips cleanly — you get built-up edge and torn surface. Stick to PVD grades (KF5900, PC5300, GC2025) for stainless regardless of depth. CVD grades work for steel at ap > 1.5 mm and cast iron.
3. What's the smallest face mill diameter I can use APMT 1135 in?
APMT 1135 (11 mm IC) works on face mills from 50 mm to 100 mm diameter. For face mills below 50 mm, use APMT 0602 (6 mm IC) — APMT 1135 inserts will overhang the cutter body. For face mills above 100 mm, use APMT 1604 (16 mm IC) for higher productivity per pass.
4. Is Korloy KF5900 equivalent to Mitsubishi VP15TF?
Approximately — both are PVD Al-Ti-N grades designed for stainless M15-M25 class at 100-180 m/min. VP15TF has marginally better performance on HRSA and aluminum; KF5900 has marginally better performance on 304/316 stainless. For most shops, they're interchangeable at the spindle. For HRSA-heavy work, prefer VP15TF.
5. Do I need HP coolant for APMT 1135 on stainless?
Yes — high-pressure coolant at 50+ bar is mandatory for stainless milling with APMT 1135 PVD grades. Flood coolant alone (2-5 bar) cannot penetrate the chip zone at the insert tip and you get rapid built-up edge. HP coolant through the cutter body or side-flush nozzles is required for tool life.
6. What surface finish can I expect with APMT 1135 PDR-K on 304?
At recommended parameters (Vc 150 m/min, fz 0.12 mm/tooth, ap 0.8 mm), APMT 1135 PDR-K delivers Ra 0.8-1.6 µm on 304 stainless. For Ra 0.4 µm (mirror finish), reduce fz to 0.05 mm/tooth and ap to 0.3 mm — but tool life drops by ~40%.
Get Expert Help with Your APMT 1135 Selection
Choosing the right APMT 1135 chipbreaker + grade + parameters for your specific workpiece (diameter, depth, material, tolerance) is what separates 50% first-pass yield from 95%+. Our engineering team can match your face milling operation to the optimal APMT 1135 combo across 8 brands and 5,880 SKUs.
Browse our face milling cutter series (APMT 1135 + APMT 1604 + APKT compatible) or see our complete stainless steel buying guide for material-specific recommendations across all stainless sub-classes.