# Pen Mandrel Thread Size?



## toomanysplinters (Nov 14, 2005)

Does anyone know that the thread size is on the mandrels that Arizona Silhouette sells?


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## Chris Hare (Nov 14, 2005)

I think it is a 1/4" dia. machine thread. 

Hope this helps.


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## Paul in OKC (Nov 14, 2005)

1/4-28 is pretty much the standard. Some older mandrels had a 10-32 thread on the end that went into the morse taper end.


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## Mudder (Nov 14, 2005)

> _Originally posted by Paul in OKC_
> <br />1/4-28 is pretty much the standard. Some older mandrels had a 10-32 thread on the end that went into the morse taper end.



Yep,

1/4-28 on all the mandrels that I own.


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## Randy_ (Nov 15, 2005)

Scott:  Others have offered the correct answer to your question; but it is worth noting that the mandrels sold by WOODCRAFT reportedly have a different thread.  I don't remember that the actual threading has ever been mentioned; but it is supposedly a little smaller than the standard 1/4 x 28.  

Since the subject has come up, think I will email WOODCRAFT and see if they will give me the information.


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## Fred in NC (Nov 15, 2005)

Before going too far with this, it would be better to find out which end of the mandrel shaft are we talking about. 

Most of the mandrels in the market have a 1/4-28 thread in the tailstock end (for the round nut).  The only exception I found is with some of the PSI mandrels.

The end that screws into the Morse plug is another story. . .


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## Randy_ (Nov 15, 2005)

My Berea mandrels(both the "A" and "B") have the same thread on both ends.  I think it is the 1/4" x 28 thread but am not sure


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## Randy_ (Nov 15, 2005)

> _Originally posted by Fred in NC_
> <br />...The only exception I found is with some of the PSI mandrels...



Fred:  What is the thread on the PSI mandrel??


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## Fred in NC (Nov 15, 2005)

What is the thread on the PSI mandrel??  --&gt; 1/4-20


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## Randy_ (Nov 15, 2005)

Thanks!!


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## Randy_ (Nov 15, 2005)

Just got a reply from WOODCRAFT:

"...It has a 5mm x 0.8 thread pitch..."


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## woodman928 (Nov 15, 2005)

Dem silly little milly meters  [][][]


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## Fred in NC (Nov 15, 2005)

Randy, please correct me if I am wrong, but is that the size of the thread that goes into the Morse taper plug ?  The nut end of all my Woodcraft mandrels is 1/4-28.


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## Randy_ (Nov 15, 2005)

Fred:  I forgot to ask that question when I emailed WOODCRAFT.  I assume it is the arbor end of the mandrel based on previous posts saying the WC mandrels would not fit other arbors.  Anyway, after realizing my mistake, I sent Woodcraft another email for clarification; but it was after 5 so I'm not expecting an answer until tomorrow.


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## KenV (Nov 16, 2005)

I ran the "screw chekr" on and off the AZ A and B and a PSI mandrel  1/4 by 28 both ends of all three --


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## scubaman (Nov 17, 2005)

Berea mandrels use 1/4-20 (1/4 NC). At least the high precission shafts do - never saw the other one.  All others I know of use 1/4-28 (1/4 NF) at the tailstock end.  Both are standard nuts available in any HW store


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## Randy_ (Nov 17, 2005)

> _Originally posted by KenV_
> <br />
> I ran the "screw chekr" on and off the AZ A and B and a PSI mandrel  1/4 by 28 both ends of all three --



"...Houston, we have a problem..."

Fred said one end of his PSI mandrel was 1/4-20.  We have a conflict here unless PSI has put out mandrels with different threads.  Fred...???...Ken...???


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## Fred in NC (Nov 17, 2005)

Well, I own ONE PSI mandrel, over 2 yrs old, and it does have 1/4-20 thread at the nut end. The other end is plain, for a drill chuck.  It was marginal, and I switched over to Woodcraft mandrels.


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## KenV (Nov 17, 2005)

I am using a Brownell's Screw Checker on a PSI Item PKM-ALX mandrel and both ends still go in the 1/4 by 28 NF hole.

Love the screw checker -- have been using this one for many years and it has save a number of wrong assumption from becoming repair opportunities.


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