Rule Clamp This useful tool is for clamping two steel rules together, end to end, making one long rule for measuring longer lengths than a single rule. Since the clamp bolts have independent adjustment, the rule clamp will hold rules of the same or different widths up to 1-1/4" (32mm). This clamp is handy for mechanics whose tool chests will not hold rules over 12" (300mm) long. Key Sea t Clamps These key seat clamps convert steel rules, combination square blades and straight edges into key seat rules for laying out keyways and scribing parallel lines on round work. They can be easily attached or removed. Made of steel, case hardened, and accurately ground, they are 1" long x 7/16" wide (25 x 11mm) and have a 7/64" (2.8mm) slot width. Available in pairs only. Clamps Key Seat Clamps Cat. No. EDP Description 298 51327 Pair of key seat clamps Rule Clamp Cat. No. EDP Description 299 51328 Rule clamp 299 300 P recision R ules , S traight E dges , P arallels