hex socket bolts

[Delwin D Fandrich]

| -----Original Message-----
| From: pianotech-bounces@ptg.org 
| [mailto:pianotech-bounces@ptg.org] On Behalf Of Ron Nossaman
| Sent: September 06, 2005 10:19 PM
| To: Pianotech
| Subject: Re: hex socket bolts
| 
| 
| > As far as I know the only tests done on this subject were by Lee 
| > Valley tools and WoodenBoat magazine. In general they found that 
| > withdrawal strength was moderately higher with untapped holes.
| >  
| > Del
| 
| I'd think that would be dependent on the compliance of the 
| material the bolt is going into, and the diameter and thread 
| pitch (read thread depth and interference fit) of same. 
| Pressing relatively smaller diameter capstans into sugar 
| pine, basswood, or spruce in keys, and pressing relatively 
| larger diameter plate support bolts with considerably deeper 
| threads into hard maple aren't going to realistically equate. ...
| _______________________________________________


The tests I referred to did not consider machine screws that were pressed in.
They were standard machine screws that were screwed in -- just without the
benefit of advance threading.

Del