Hand tools for service in corrosive environments

Hand tools for service in corrosive environmentsKeywords: Carpenter Specialty Alloys,Stainless steel, Tools

A new line of high-performance, stainless steel hand tools claims a combination of attributes that have been considered useful to the medical,biomedical, biotech, pharmaceutical, food, nuclear, marine and other industries concerned with clean room sterility and/or exposure to corrosive environments.

SteriTool, a division of US-based Nautitool, Inc. specializing in stainless steel tools, has introduced a line of conventional screwdrivers, L- and T-pattern hex keys, and ball-end L-pattern hex keys (Plate 3). All of the tools have been made from Custom 465 stainless, a specially alloy recently developed for aerospace applications by Carpenter Technology Corp.

Tools made from the Carpenter stainless are reported to combine high strength, high hardness, high toughness, and the torque capability of the most suitable carbon steels, with superior resistance to both general corrosion and stress corrosion cracking. The corrosion resistance exhibited by Custom 465 stainless is reported to approach that of Type 304 stainless steel.

  Plate 3 Sampling of SteriTools™ that have been made from Carpenter Custom 465®stainless includes a 6.0mm long L hex key (top), a ÷in. x 6in.-long screwdriver,a 5.0mm ball-end L-pattern hex and a ÷in. T-pattern hex key

All of the tools are stated to be autoclaveable and totally resistant to surface oxidation in a steamy environment. This characteristic is believed to eliminate the possibility of contaminating the atmosphere with fine particulates that are sometimes generated when autoclaving plated carbon steel or chrome-vanadium steel tools.

Custom 465 stainless is a premium-melted, martensitic, age hardenable alloy. In the solution annealed and aged (H900) condition, this alloy is reported to be capable of about 260ksi (1,793MPa) ultimate tensile strength. In this condition it is said to have excellent notch tensile strength and fracture toughness.

In small diameters (less than 0.750in.), Carpenter also produces this alloy in the solution annealed and strain hardened (ANL SH) condition. When this material (ANL SH) is aged to the H900 condition, the ultimate tensile strength approaches 300ksi (2,069Wa), while the 0.2 per cent offset yield strength approaches 290ksi (2,000bTa). Because the yield strength and the tensile strength are so close together, the tool will bend before it breaks. This tendency makes the tool safer to use.

SteriTool, which reports that the stainless machines well, centerless grinds eight different sizes of screwdrivers and hex keys, from 0.100in. to 0.393in.(2.5mm to 9mm) from stainless bar stock. The screwdrivers are offered with nylon handles and flat, Phillips and Robertson square drives. The L-hex and T-hex keys also come in the same size range.

The tool manufacturer says he is the only one who has made Custom 465 stainless steel ball-end hex keys that are available worldwide. These tools are available in sizes of 1/16in. to 3/8in. (3mm to 8mm) measured across the flats of the hexagon.

SteriTool's tools that have been made with Custom 465 stainless are stated to meet all manufacturing standards established by the FDA. They are also said to meet all AISI specifications for tools in the USA, and DIN specifications for tools in Europe.

Details available from: SteriTool Tools. Tel: +1 718 852 3620; Fax: +1718 852-6931; E-mail: info@steritool.com

Details available from: Carpenter Specialty Alloys. Tel: +1 610 208 2235;Fax: +1 610 73 6 7077; E-mail: jdahl(@cartech.com