STI International slides are CNC milled from pre-hardened barstock 4140 carbon steel to ensure slide rail exactness. The breech face is wire EDM cut for maximum precision angle. These are available in either 5″ (Government), or 6″ (Long Slide). The slides have lowered and flared ejection ports for reliable case ejection. STI slides fit both 1911 and 2011 frames. 355 is compatible with 9mm, 38 Super and similar cartridges. 400 is compatible with 40 S&W and similar cartridges. 450 is compatible with 45 ACP and similar cartridges.
1911, Issue:11, Page:002
Big Book Catalog, Issue:68, Page:101
SPECS: 4140 Carbon Steel.