Shopsmith Forums

Why is the 1" 1/4 saw arbor left hand thread and the 5/8" arbor right hand thread??

Art

beeg wrote:Just a WAG here. It's because of the rotation and the 5/8" has a tonged washer?????

Because they are on opposite sides of the blade. The resistance of the cutting causes the nuts to tighten. The 5/8" has a tongued washer to prevent the blade inertia when 'stopping' from loosening the nut. The 5/8" has less ability to 'hold' the blade than the 1 1/4" due to surface area of the face of the nut. Also the 1 1/4" 'captures the blade(it CANNOT fly off even if the nut comes loose. If the nut on the 5/8" comes loose(to the point of falling off) the blade may also come off the end of the shaft and ricochet off the floor and walls and.....

Good explaination, JP!

JPG40504 wrote:If the nut on the 5/8" comes loose(to the point of falling off) the blade may also come off the end of the shaft and ricochet off the floor and walls and.....

That mental picture you just painted should make everybody give a little extra tug on the wrench as they tighten it...

Hi,

I am in full agreement with JPG's answer to the original question regarding the thread direction (left or right hand) being based on which side of the saw blade (or other cutting device) that the nut is mounted on.

However, a couple of things from my SS arbor experiences:

Tongue Washers:

I have never seen a SS Saw Arbor with a tongue washer (5/8" Molder/Dado Arbors and 1/2" Shaper & Aux Arbors yes, Saw Arbors no).

Nut Size (outer diameter):

My SS 5/8" Saw Arbor's nut has the same surface area as a SS 1-1/4" Saw Arbor. Other SS arbors such as the Molder/Dado Arbor do have a smaller nut and the tongue washer, but I have never seen a "small" nut on a SS Saw Arbor.

I realize that some folks routinely mount their 5/8" bore saw blades on non-saw arbors without any problems, but if there are SS Saw Arbor variations out there, I would like to hear about it if any of you have one.

Best regards to all,

Dennis

What I ordered was this

555321 - 5/8" Arbor 500

It does not have a tongue washer and it does have the same surface area as the 1 1/4 arbor. I am not seeing what you guys are talking about with the blade mounting on the other side with the 1 1/4 arbor. I will have to get both of them side by side and compare maybe to see it.

I have found that there are two arbors for a 5/8" saw blade hole. One where the tightening nut is on the right hand of the blade and one where the nut is on the left hand of the blade (like the 1-1/4" arbor). The arbor with the nut on the right hand side has a clockwise thread where the arbor with the nut on the left hand side has a counter-clockwise thread.

Perhaps you may be having difficulty understanding what is being said because your 5/8" arbor looks just like the 1-1/4" arbor with the counter-clockwise thread.

I now understand it once I looked at both arbors.

And a little locktite might be in order to help things out. Why wouldnt they make the stud on the arbor a little longer and drill it so you could put a cotter pin in there to help things as well?

wholeshoe wrote:What I ordered was this

555321 - 5/8" Arbor 500

It does not have a tongue washer and it does have the same surface area as the 1 1/4 arbor. I am not seeing what you guys are talking about with the blade mounting on the other side with the 1 1/4 arbor. I will have to get both of them side by side and compare maybe to see it.

You are correct! That 'new' style does not have nor need the tongued washer. As you have observed, the nut face area approximates that of the 1 1/4" nut.
Us fossils are used to the older type with a smaller nut.(and tongued washer)[long time ago this was the ONLY kind.]
The threaded stud length IS short intentionally to prevent using it for something other than a saw blade.
The inertia of the saw blade is low enough to not need the tongued washer.

Locktite - Bad idea You might want to change blades someday.
Cotter pin - Bad idea You do not need cotterpins flying around the shop. They have been known to come loose!