- Truncated Cone Saw Bolts & Nuts -

For a relatively brief period in the mid to late 19th century, Disston and other saw makers adorned some of their saws with bolts and nuts whose heads are best described as truncated cones. With their hardware standing well proud of the handle, these saws possess a bold and distinctive air.

Because they soon fell out of favor, replacement bolts and nuts for these saws are hard to come by. Now, 150 years later, I am pleased to finally offer a modern version of this hardware. These new bolts are available in large and small variants.

For those making new handles, this is very simple and forgiving hardware. Because the heads are not sunk into counterbored holes, a clean installation is not dependent on precisely drilled holes. To further ease installation, the slots on these nuts (unlike those on split nuts) require no specialized screwdriver or spanner.

The bolts have square shanks that can be mortised into the handle to prevent rotation when tightening the nut. Threads are a standard 8-32 pitch.

Both bolts fit saw handles ranging from 9/16" to 1 1/16" in thickness. You will need to cut or file the threaded portion to length, a relatively simple task. Instructions for doing so are below, and are also included with each order.

Large: While these are not an exact replica of the originals, they are a reasonably close match and can be used as replacements for missing or mangled hardware (or on new saws or handles). The differences between these and the originals are enumerated below.

• While the originals were cast, these are machined from solid brass stock. The overall geometry matches the originals, but the new ones are much more uniform in appearance. In particular, the sides of the originals have a non-uniform taper that is a byproduct of the casting process.
• The undersides of the original bolt heads are recessed. While this may have been done to save material, to ensure flush seating, or for some other reason, I do not find it necessary on the new ones.
• The shanks on the original nuts are tapered, probably for easy release from the mold. The new ones are not tapered, but are sized to fit in the original holes.
• The threads on the originals and the new ones are NOT INTERCHANGEABLE, but the new and old diameters (0.160" for the major diameter of the bolt) match closely.
• Finally, keep in mind that the originals were used by many makers, and these may not match all of them. To determine if they will work for your saw, please refer to the dimensioned drawings.

Dimensions:

• The nut has a slot that is 0.050" wide, and requires no specialized screwdriver or spanner. To avoid mangling the slot, please select a properly fitted screwdriver.
• The maximum diameter of the bolt and nut heads are 0.530"; their heights are 0.205".
• The bolt shank is 0.160" square (requires drilling a 5/32" hole)
• Optional washers (zinc-plated steel) have a 3/4" outside diameter.
• For further dimensions, please refer to the dimensioned drawings.

Small: These are similar to the large bolts, but the bolt and nut heads are scaled down to better fit backsaws and smaller panel saws.

Dimensions:

• The nut has a slot that is 0.032" wide, and requires no specialized screwdriver or spanner. To avoid mangling the slot, please select a properly fitted screwdriver (this may require some grinding of the blade to thin it out).
• The maximum diameter of the bolt and nut heads are 0.430"; their heights are 0.125".
• The bolt shank is 3/16" square (requires drilling a 3/16" hole)
• Optional washers (cadmium-plated steel) have a 5/8" outside diameter.
• For further dimensions, please refer to the dimensioned drawings.

If you find that these will not work for your saw, and need custom bolts, please contact me for a quote.

Installation notes: Measure the thickness of the handle (including any washers that will be used under the heads of the bolts and nuts). This is the length to which the shank of the bolt will be cut. Before shortening the bolt, thread the included hex nut onto the bolt so that it is past the excess length.

The bolt can be shortened with either a hacksaw or file. After cutting or filing, remove the hex nut. This will reform the threads at the very end of the bolt, making it easier to thread the actual nut onto the bolt.

The optional washers come with a zinc or cadmium plating. For a more traditional look, this plating may be removed by an overnight soak in household vinegar.

Resources: Making your own saw, while a very rewarding project, can be daunting. While there is no substitute for actually making one, many of us are not inclined to jump right into things. These resources will help you get started on your saw.

• This series of blog posts covers the construction of a saw from start to finish.
• A variety of saw handle templates are available as downloadable pdf's. I will fill out the entire range as they are completed.

Other saw parts: If you need other parts for your saw, I sell split nut saw bolts, toothed backsaw blades, and slotted saw backs. Or buy a slotted back saw kit and save a few dollars.

Made in the USA.