Thompson steel precision-honed tubes are constructed of 1026 cold-drawn carbon steel which has a yield pressure of 75,000 psi. Ultimate strength is more than 90,000 psi. These tubes are straightened and honed to base to provide excellent wear-resistant qualities.
Heat Treated Precision-Honed Tubes
Thompson heat treated precision-honed tubes are constructed of 1015 cold-drawn carbon steel. They are suspended in liquid carburizing salts for 4-1/2 hours at 1,750 degrees F. This process results in a depth of case of .020 of an inch plus on the ID and OD scale and a tensile strength of 86,250 psi. The ID and OD surface will be Rockwell 56 to 60 plus on the C Scale direct.
Core Rockwelling of only 10 to 15 on the C Scale makes these tubes especially shock resistant.
Toma Chrome Plated Precision-Honed Barrel Tubes
In these models, Thompson applies hard chromium plating to 1040 cold-drawn tubing to a thickness of .003 of an inch or .006 of an inch on the diameter. (It has been standard practice for many years to plate barrels .006 on an inch on the diameter.)
This operation insures hardness, toughness, and durability to act independently of the base metal. Chromium plating checks 72 Rockwell on the C scale.
Bronze Precision-Honed Tubes
Thompson bronze precision-honed tubes are made of hard-drawn Admiralty bronze with a minimum Rockwell B hardness of 90 and a tensile strength in excess of 90,000 psi. The tubes are straightened and honed to base.
Bronze precision tubes are also available with chromium plating of .003 inch on the wall or .006 of an inch on the diameter.
Thompson Hard-Face Plungers
Thompson uses AMS 4775A chromium-nickel-boron self-fluxing alloy to construct these hard-face plungers. Hardness is 60-63 on the Rockwell C Scale with a thickness of .020 of an inch on the radius. Hard-face plungers are highly wear and corrosion resistant.
The hard facing is sprayed on 1015 cold-drawn tubing. The coating is fused to the base at 1,950 degrees F., and the plunger is then slow cooled, straightened and precision ground. Available in pin and box end.