Wexmar provides S7 and H13 tool steel CNC machining for tooling that has to survive impact or high temperature. S7 is a shock resisting grade used where parts are struck or loaded suddenly. H13 is a chromium hot work steel that keeps its hardness and resists heat checking when it runs against molten or hot metal. Our Canastota, New York shop machines both grades from annealed bar and plate, and H13 from prehard stock when a design calls for it.
S7 and H13 machinability
Both grades carry an approximate machinability rating of 45 against AISI 1212 at 100 in the annealed condition. That places them close to O1 and ahead of D2. H13 bought prehard, commonly in the mid 40s HRC, cuts much more slowly than annealed stock and needs harder carbide grades, but it avoids a separate heat treat step for parts that do not need higher hardness.
Tolerances and surface finish
Typical tolerances on annealed S7 and H13 are plus or minus 0.001 in on milled and turned features, with 63 Ra typical on milled surfaces and 32 Ra on turned diameters. Molding and die faces that need a finer finish are usually polished after hardening, which is sourced outside when required. Critical fits are left with grind stock and finished on our in-house surface or centerless grinders after heat treat. These are typical values that depend on part size and shape.
Shop knowledge for S7 and H13
- Tough chips. S7 is designed to absorb impact, and it resists shearing the same way. Positive rake inserts with strong edge prep and steady coolant prevent chipping and built-up edge.
- Prehard H13. Machining H13 near 44 to 46 HRC calls for rigid workholding, lower surface speeds and wear-resistant coated carbide. Drilling is the slowest step, so through-coolant carbide drills are standard.
- Cooling lines in die inserts. Die casting and mold inserts often carry long cross-drilled cooling passages. Hole straightness and breakthrough burrs at intersections need attention so water lines seal and flow cleanly.
- Heat treat movement. Both grades air harden and move less than oil hardening steels, but large blocks still need finish stock on locating and sealing surfaces.
- Decarb and stress. Remove the decarburized surface from annealed bar, and stress relieve heavily roughed blocks before finish machining.
Heat treat and finish options
Through qualified outside processors, we arrange vacuum hardening and multiple tempers to the drawing hardness, with S7 typically run in the mid 50s HRC and H13 commonly in the mid to high 40s HRC for hot work service. Nitriding is a frequent add for H13 die casting tooling, and black oxide or PVD coatings are available. Parts return to our floor for final grinding and CMM inspection.
Common S7 and H13 parts
- S7 punches, chisels, rivet sets, shear blades and stamping tools that see shock loads
- H13 die casting inserts, core pins, ejector components and shot sleeves
- H13 extrusion dies, mandrels and hot forging tooling
- Plastic injection mold inserts and slides in prehard H13
- Heavy duty locating pins and fixture details that must not chip
Inserts and blocks suit our 4-axis horizontal machining centers, which reach several faces and drill cooling lines from multiple sides in one clamping. Core pins and punches are turned, and smaller pins up to 32 mm diameter run on our Swiss-type machines.
Cost index: S7 and H13 vs related grades
| Material | Approx. machinability (1212 = 100) | Cost index vs 6061 | Notes |
|---|---|---|---|
| 6061-T6 aluminum | ~180 | 1.0 | Reference |
| 4340 annealed | ~57 | 2.0 | Tough alloy steel, lower cost |
| A2 annealed | ~42 | 2.5 | Cold work, air hardening |
| D2 annealed | ~30 | 2.5 | Cold work, abrasion resistant |
| S7 annealed | ~45 | 2.6 | Shock resisting |
| H13 annealed | ~45 | 2.6 | Hot work, resists heat checking |
The index is typical and illustrative for a comparable part; actual quotes depend on geometry, quantity, tolerances and mill pricing.
Applications and industries
S7 parts go to stamping and assembly lines, fastener production and maintenance tooling. H13 serves aluminum and zinc die casters, extruders, forging shops and plastic molders. Many of our tooling customers are industrial OEMs and captive toolrooms that need build-to-print replacement components on a predictable schedule; see our industries page for the sectors we support. For cold work wear parts instead, the A2, D2 and O1 tool steel page covers those grades.
Getting a quote
For S7 or H13 tooling, upload a drawing for an instant estimate or call (315) 400-2654. A human estimator confirms every quote, including material condition, heat treat and any nitriding.