Set Screw For Flat Sanding Disc Arbor

algale · Post by **algale** » Sat Feb 23, 2013 6:56 pm

1. I have 2 sanding discs (current steel versions with the long arbors that let you use them with the 510/520 lower saw guard. Once of these discs came from a source that makes me think it may have a non-original set screw. But unfortunately I can no longer tell which disc is which. I need to replace one of the set screws. Can anyone verify the size/length and point type of the set screw that it this arbor should come with from Shopsmith and a source (other than Shopsmith)?

2. Has anyone ever had the socket in the head of a set screw go bad? I thought it was the end of my Allen Wrench rounding over but when I pulled out a nice new 5/32 Allen Wrench, it spun in the set screw's socket. That's a new one for me.

Al

JPG · Post by **JPG** » Sat Feb 23, 2013 7:21 pm

Here is my 'opinion' of what the set screw should be.

Thread 5/16"-18
Socket 5/32"
Length When tightened on arbor, flush +- 1/32" minus preferred
End oval

I would be real suspicious of the worn socket one!:eek:

algale · Post by **algale** » Sat Feb 23, 2013 7:24 pm

JPG40504 wrote: End oval

What's the reason for an oval end on an arbor set screw?

JPG · Post by **JPG** » Sat Feb 23, 2013 7:46 pm

algale wrote:What's the reason for an oval end on an arbor set screw?

1) It will not chew on the shaft.
2) It is tolerant of de slope of de shaft flat.

Flat tis a second choice, but I think they tend to loosen easily again due to the slope.

However if the set screw hole is bored at an angle so as to be perpendicular to the flat, a flat screw end is more gooder!

All JMHO!;)

Mike907 · Post by **Mike907** » Sat Feb 23, 2013 7:58 pm

The set screw from my new in the box sanding disk (555143) is flat pointed.

dusty · Post by **dusty** » Sun Feb 24, 2013 4:57 am

The set screw on all of my sanding and saw arbors are flat.

JPG · Post by **JPG** » Sun Feb 24, 2013 10:32 am

dusty wrote:The set screw on all of my sanding and saw arbors are flat.

Must be a MV thingey!:D

dusty · Post by **dusty** » Sun Feb 24, 2013 12:08 pm

Mike907 wrote:The set screw from my new in the box sanding disk (555143) is flat pointed.

I do not mean to be sarcastic but is it flat or pointed? I assume you are saying it is flat tipped which is what mine are.

Mike907 · Post by **Mike907** » Sun Feb 24, 2013 5:10 pm

I thought the phrasing was confusing, also. It's from the Shopsmith Parts list -
Part No. 222460 Flat Point Setscrew, 3/8" lg.

Mike

dusty · Post by **dusty** » Sun Feb 24, 2013 5:46 pm

Mike907 wrote:I thought the phrasing was confusing, also. It's from the Shopsmith Parts list -
Part No. 222460 Flat Point Setscrew, 3/8" lg.

Mike

I just noticed that you are in Anchorage. My oldest grand daughter and her husband left there about six months ago when he separated from the Army.

May I offer the following chart of set screws. It is not all inclusive and is lacking some detail.

[ATTACH]20324[/ATTACH]

Note that I have used the term "flat point" or "round point" just as you did.