During the 1930s and 1940s these pliers were available only in an 8 inch size.
The Craftsman name in block text and the model number marking suggest an earlier date within this range. 188 shows a pair of Craftsman Vanadium 6.5 inch slip-joint combination pliers, stamped "Vanadium" below the Craftsman underline logo, and with a "41AM" code on the underside of one handle (see inset).The overall length is 6.5 inches, and the finish is polished nickel.Several types of probable manufacturer's codes have been observed on Craftsman pliers.One fairly common marking is a stamped or forged "C" inside a circle, typically placed on the inside of the handles near the ends.A friend of mine just bought a Craftsman #1 plane, still in mint condition in mint condition original box. He paid .00 and believes it is worth over 00.00. I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation! My friend is a kinda cagy trader and sometimes won't reveal his stuff.
He owns a large flea market/antiques mall and gets first dibbies on everything booth renters bring in.
Unfortunately, many plane types share the same bed markings, so other features are also used in dating.
Some plane parts were frequently replaced by their owners, or are easily separated from the plane, such as irons, cap irons, knobs and totes, and lever caps.
The top inset shows a side view of the pliers, illustrating the "Nested Diamonds" gripping pattern on the handles.
The small inset shows a close-up of the "41AM" code stamped on the underside of one handle.
The overall length is 8.3 inches fully extended, and the finish is polished nickel.