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Terminology for Jaws

There are two kinds of jaws: through and stopped. A through jaw has two threaded holes through it. A stopped jaw has two smooth holes, one goes through, and the other does not

The places on a jaw are conventionally (by me) called:

For a stopped jaw, we can also define

And similarly for a through jaw.

I hang my clamps with the middle spindle going up, the end spindle going down, nose away, and then "right" falls right out. It is a convention, and an arbitrary one at that.


Shape is the most distinctive characteristic to determine maker, but size is also useful to distinguish models when the model number is worn or marred.


Is there a distinct edge between the back and the outside face, and between the outside face and the angle?

No: a Hood , or Hood and Rice.

Yes: check the chamfering, which is

some makers always (AFAIK) used flat chamfering: Bliss, Narragansett, Hood;
some makers always (AFAIK) used beaded chamfering: Aldrich;
some makers offered beading as an extra cost option: Chapin.

Five (5) Edges

five chamfered edges, along nose, and outside

Is the chamfering flat, and uniform, along five edges? Yes: either Narragansett (when chamfer is closer to horizontal) or Grand Rapids ( when the chamfer is closer to vertical)
Is the chamfering flat, and tapering down the nose, along five edges? Yes: a Bliss company
Is the chamfering rounded, along five edges? Yes: Sandusky or Sargent
(These appear to have identical chamfering.)
Is the chamfering "stepped", along five edges? Yes: Dodge Manufacturing

See note about Greenfield Tool Co..

Six (6) Edges

six chamfered edges, along nose, outside, and end

Is the chamfering flat, and tapering down the back, and down the angle, along six edges? Yes: Hood

Eight (8) Edges

eight chamfered edges, along nose, and outside, and around end

Is the chamfering half-round, along eight edges? Yes: Sandusky
(I have one example of this, and it might be wear!
The other examples have half-rounding on 5 edges.)

Ten (10) Edges

ten chamfered edges, along tip, nose, outside, and around end

Is the chamfering half-round, along ten edges? Yes: Aldrich, or Webster and Butterfield


Hood et al.

These clamps have a graceful curving transition from outside face to adjacent faces. Also, the chamfer starts narrow at the back, widens, is uniform along the outside, then narrows along the angle. Lastly, their top and bottom sides are not parallel.

The Bliss Companies

These, including ONeil, have exactly the same chamfering.


The several known specimens by Buttrick all vary among themselves.


I have only one specimen of Stanley; John Adams is helping in the research on this maker.


I have only a few specimens of Sargent; I hate to generalize.

Greenfield Tool Company

The illustration in the catalog of 1872 shows a flat chamfer, rather Bliss-like, but the details are obscure. I hope someone has a specimen I could examine.


See the Model pages for dimensions of jaws.

Regional Types

The Rhode Island companies have flat chamfers, while the eastern Massachusetts companies have more complex chamfers.

There is no Connecticut type.

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