All jaws come standard made from A2 Tool Steel, heat treated to 55~ Rockwell
**I offer other options as well: smooth tool steel, solid aluminum, solid brass, solid bronze, solid copper. Price varies depending on materials used; contact me for more information**
**READ** ALL COLUMBIAN JAWS REQUIRE SOME WORK FROM ON YOUR END:
You will receive the jaws PRE-hardened. You will likely have to lightly hand file/sand to get the jaws to fit as Columbians often take a beating to get the jaws off and the tolerances were not completely accurate.
You will THEN be required to drill/ream your own pin holes. After this you will mail them back to me for final heat-treating before being able to use the jaws. 
I AM NOT RESPONSIBLE FOR DRILLING MISTAKES OR LOST PACKAGES ON RETURN SHIPPING TO ME. PACKAGE THEM WELL, INSURE THEM IF YOU'D LIKE, THAT IS UP TO YOU.
 
These fit the following models:
Columbian #504/#604 M2 (UNCONFIRMED, CHECK MEASUREMENTS & CONTACT ME FIRST)
 
Length: 4.078"
Height: 1.250"
Thickness (INCLUDING T-SLOT): 1.000"
Depth of T-slot: 0.500"
Thickness of T-slot: 0.375"
 
**Jaws are usually stocked but sometimes must be made-to-order if I am running low. Your order will be created and shipped on a first come, first serve basis. Thank you!**