Metallic mold materials: product lines reviewed.

ALUMINUM CO. OF AMERICA

A leading producer of wrought aluminum plate for use as mold material in blow, injection and compression molds. Alcoa QC-7 mold plate is designed specifically for blow and injection molding applications where high strength, high thermal conductivity and superior hardness is required. For applications requiring thickness from 6 through 20 in., company offers 6061 mold plate in two tempers.

AMPCO METAL, INC.

Offers copper alloys for blow and injection molding. Three high-conductivity copper alloys--Ampco 97, Ampco 940 and Ampco 945--provide mold designers the ability to optimize thermal conductivity, hardness, corrosion resistance and wear resistance. They are said to be cost-effective alternatives to beryllium copper. The alloys provide thermal conductivities of 80-190, thermal diffusivities of 1.42-3.76, and hardness of 143-290 Bhn. Recommended applications include molds and mold inserts, pinch-offs, blow and core pins, lifters, guide-pin and leader-pin bushings, and unscrewing mold components. Both conventional machining practices and EDM methods can be employed. Surface finishes of 4 RMS are possible. Alloys are readily welded to accommodate stainless-steel overlays. Company stocks alloys in standard sizes of bar, rod, tube and plate.

BRUSH WELLMAN INC.

Company's beryllium copper alloys, Moldmax and Protherm, reportedly improve the performance of injection molds. Benefits include reduction in cycle time and better dimensional control, based on a rapid and more uniform removal of heat from the plastic part.

CRUCIBLE SERVICE CENTERS

Supply a full line of mold steels, including stainless grades for molding highly abrasive engineered resins, and copper alloys for rapid heat dissipation in molds. Tough, wear-resistant tool steels for compounding and pelletizing also are offered. Company offers custom cutting, technical assistance and research.

D-M-E CO.

Offers six grades of mold steel, three for structural sections and three for cavities and cores. Structural steels include: D-M-E No. 1, a medium-carbon SAE 1030 grade; D-M-E No. 2, an AISI 4130 grade, preheat-treated to 269-321 Bhn (28-34 Rc); and D-M-E No. 7, a modified AISI 420-F holder-block stainless, preheat-treated to 305-342 Bhn (33-37 Rc).

Cavity and core grades include D-M-E No. 3, a P-20 type steel preheat-treated to 277-331 Bhn (29-36 Rc); D-M-E No. 5, an H-13 type hot-work steel, annealed to approx. 200 Bhn (13-20 Rc); and D-M-E No. 6, a T-420 type stainless, annealed to 200-240 Bhn (14-23 Rc).

A. FINKL & SONS CO.

Producer and distributor of hot-work mold steels. The steels are melted using the patented V.A.D. degassing system and further refined in a V.A.R. furnace for a double-vacuum-produced product. All mold steels are upset-forged, utilizing wide dies with a minimum reduction of area of 5:1. AISI-type P-20 and 4140 steels are cold-water quenched for maximum grain refinement and through-hardening, and then machined and sonic examined to industry standards. Modifications of P-20, 4140, Holder Block, 420 S.S. and H-13 (air-melted and double-vacuum-melted) are available, depending on application.

HASCO-INTERNORM CORP.

Offers five grades of tool steels, including AISI/SAE types 1020, P20, and H13.

TOKYO BOEKI STEEL

Company's new PX-5 steel reportedly has a more refined grain structure than P-20 steel, and is said to polish to a better finish. It's also said to have twice the toughness of typical Cr-Mo materials, eliminating problems of cracking.

THYSSEN SPECIALTY STEELS, INC.

Manufactures the following tool steels for moldmaking:

* Thyssen 4140 modified holder, preheat-treated (24/32 Rc), is a free-machining alloy tool steel designed specifically for mold-base materials.

* Thyroplast 2311, AISI P-20 modified, preheat-treated (28/34 Rc), is suitable for molds.

* Thyroplast 2738, AISI P-20 modified, preheat-treated (28/34 Rc), is suited for large plastic molds requiring high core hardness.

* Thyssen P-20 Super, AISI P-20 modified, preheat-treated (38/42 Rc), is suitable for plastic molds where electrochemical or photo-etching is required, and where long runs are necessary.

* Thyroplast 2316 FM, AISI 420 F modified, preheat-treated (30/38 Rc), is a free-machining, corrosion-resistant tool steel intended for mold frames, holders and boosters for all types of molding.

* Thyroplast 2083 Supra, AISI 420 modified, in the annealed condition, is an electroslag-remelted stainless steel capable of being heat-treated to high hardness, and is particularly suited to compression and injection molding, which require exceptional polishability, long runs and/or corrosion resistance.

* Thyrotherm 2344 Supra, AISI Premium H-13, in the annealed condition, is an electroslag-remelted, hot-work tool steel capable of being heat-treated to high hardness with excellent toughness, and is suitable for molding with excellent polishability where corrosion is not a factor.

UDDEHOLM CORP.

Offers a full range of mold steels and complementary tooling products. Mold steels include Impax Supreme, P20 modified, premium-quality, pre-hardened grade with reportedly excellent polishing and photo-etching properties; Orvar Supreme, H13 modified, through-hardening mold steel said to have excellent machinability, polishability and toughness; and Compax through-hardening steel with good toughness at high hardness and moderate wear resistance. Rigor (A2) is a medium-alloyed mold steel with high wear resistance. For very high wear resistance, ASP 23 and Vanadis powder-metallurgy grades are available.

Also available are stainless mold and holder steels for low-maintenance, long-run operations. Grades specially developed for optimum tool performance include Stavax ESR, 420F modified, through-hardening mold steel with good corrosion resistance, high wear resistance and excellent polishability, according to the company. Ramax S, 420F modified, is a pre-hardened holder or mold-base steel said to have excellent machinability and good resistance to indentation. Elmax is a wear-resistant powder-metallurgy stainless grade recently introduced for cavity insert molds that process abrasive engineering resins.