Model A & B

Ford Garage

Snap-on Cylinder Head Nut Wrench

This Snap-on cylinder head nut obstruction wrench is the perfect wrench to use on the Model A and Model B engine!

The wrench is 1/2 inch square drive and 11/16 twelve point box, and is an obstruction offset style wrench. It has the drive end located exactly over the box end, so it is used with a 1/2 inch torque wrench directly with no offset correction needed. The torque is applied exactly in line with the stud and nut axis.

The dogleg in the wrench gets around the water hump in the head, as well as accessing the nut under the distributor without disturbing or removing anything.

This wrench also accesses all the intake and exhaust manifold nuts, with carburetors installed, including aftermarket Weber carbs and manifolds, and downdraft manifolds shown on my other pages. Not cheap, but an amazingly useful tool!

These genuine Snap-on obstruction offset wrenches are far superior to the crude fabricated wrenches intended to do the same job and sold by some of the Model A reproduction parts suppliers.

These obstruction offset wrenches are found in two sizes. The original and the 'A' suffix are both about 8-1/2 inches long, while the 'B' suffix is about 7-1/4 inch long. Both lengths work fine on a Model A.

There is also an identical version obstruction offset wrench made by Bonney which is about 8-1/2 inches long, and equal in quality to the Snap-on.

For Sale:
These 11/16 inch cylinder head nut wrenches have been out of production from Snap-on for quite a few years now, but I often have a couple of nice used ones available for sale for $60 each.
I also currently have three NOS Bonney's for $45 each.

Bonney on the left, Snap-on on the right.


More related information on Ford Garage:

  1. For more Model A & B related information, use the Site Search box at the top or bottom of this page.
  2. Model A & B Cylinder Head Gasket Guide comprehensive listing
  3. Model A & B Cylinder Head Compression Ratios
  4. Model A & B Cylinder Head Nut Tightening Sequence
  5. Model A & B Cylinder Head and Distributor Pullers by Ron Cloat
  6. Model A & B Cylinder Head Stud Removal Tools
  7. Model A & B Broken Cylinder Head Stud and Bolt Removal

April 2003