Block Plane blade O1 1 3/8" wide with 7/16" slot width

It seems the BLOCK PLANE is the workhorse of many cabinet shops. Although taken for granted, this is a very handy and versatile tool. And, like the larger bench planes, it responds well to a better blade and a little TLC. These blades will fit Stanely and Record Block Planes and they may fit others. High Carbon or Cryogenically Treated A2 Tool Steel.All are 3/32" thick x 4 1/4" Long.High Carbon Steel:1 3/8" wide with 7/16" slot width #BL1381 5/8" wide with 7/16" slot width #BL1621 3/8" wide with 5/8" slot width #BW1381 5/8" wide with 5/8" slot width #BW162A2 Block Plane Blades:1 3/8" wide with 7/16" slot width #BLA1381 5/8" wide with 7/16" slot width #BLA1621 3/8" wide with 5/8" slot width #BWA1381 5/8" wide with 5/8" slot width #BWA162Which one fits my plane?Our Block Plane Blades are available in Two Widths: 1-3/8" for Stanley-Style Low-Angle planes and 1-5/8" for the 9-1/2, et al. And There are Two Slot Configurations: 5/8" Wide Slot for new(er) Stanley planes and 7/16" Narrow Slot for the Old(er) Planes. And to further muddy the water, you have two alloys to choose from:Our High Carbon or Cryogenically Treated A2* Tool Steel. (I recommend A2 for all you bamboo fly-rod makers. It holds up much better to the abrasiveness of bamboo.) Get it?*A2 blades have an "A" in the part number.