Phillips Screws
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There is another recessed, or "cross-head" screw in common use...It is called "Reed and Prince"...Phillips has gained more popularity, but Reed and Prince, in my humble opinion, is a better format...Phillips uses different size tips and the tips are blunt, or rounded...Reed and Prince tips are sharp pointed...A single Reed and Prince tip will properly fit any size Reed and Prince screw...That was their intention in order to simplify production and cut down on the number of tools required...If a Reed and Prince tip is used on a Phillips screw, the sharp-pointed tip will most likely bottom out before the side flutes are properly engaged and a tear-out of the screw head will result...If the # 2 Phillips tip you is using has a sharp point, it is most likely not a Phillips at all, but a Reed and Prince...Grinding the tip down a little to remove the sharp point might help...Reed and Prince is an old American fastener company, incorporated in 1902, and they developed the "cross-hea
d" screw in 1938... There are anti-seize compounds available for automobile spark plugs in order to keep the steel threads of the spark plugs from seizing and stripping out the threads in an aluminum cylinder head...A small amount on the screws at the 2-D blocks should help prevent corrosion galling... Jerry, wa2dkg _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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For an exhaustive discussion on screw types, see
http://www.lara.com/reviews/screwtypes.htm and then scroll down to the 3rd description. The principal difference at the driver bit tip is that Philips bits are rounded, and thus more prone to trashing the screw than is Reed and Prince bit that is squared off. My preference is to use Reed and Prince cap screws and the proper driver for them. Bob Rennard N7WY ----- Original Message ----- From: "Jeremiah McCarthy" <[hidden email]> To: <[hidden email]> Sent: Thursday, September 29, 2005 7:18 AM Subject: [Elecraft] Phillips Screws > There is another recessed, or "cross-head" screw in common use...It is called "Reed and Prince"...Phillips has gained more popularity, but Reed and Prince, in my humble opinion, is a better format...Phillips uses different size tips and the tips are blunt, or rounded...Reed and Prince tips are sharp pointed...A single Reed and Prince tip will properly fit any size Reed and Prince screw...That was their intention in order to simplify production and cut down on the number of tools required...If a Reed and Prince tip is used on a Phillips screw, the sharp-pointed tip will most likely bottom out before the side flutes are properly engaged and a tear-out of the screw head will result...If the # 2 Phillips tip you is using has a sharp point, it is most likely not a Phillips at all, but a Reed and Prince...Grinding the tip down a little to remove the sharp point might help...Reed and Prince is an old American fastener company, incorporated in 1902, and they developed the "cross-hea > d" screw in 1938... > > There are anti-seize compounds available for automobile spark plugs in order to keep the steel threads of the spark plugs from seizing and stripping out the threads in an aluminum cylinder head...A small amount on the screws at the 2-D blocks should help prevent corrosion galling... > > Jerry, wa2dkg > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Jeremiah McCarthy
Will reply to the topic of corrosion with chassis screws on this thread.
The reply from John, G4BOU on the subject of lubricating chassis screws to help prevent corrosion was: < 'petroleum jelly' despite being a very good insulator has a lubrication factor of 1 and any pressure (via the screw threads) will break through the skin and make good contact. It will of course also cover the joint and limit corrosion.> It sticks in my mind there was some controversy with the use of petroleum jelly for use in preventing corrosion on lead acid battery terminals as it was reputed to be hygroscopic, i.e. attracts water. This may not be a good property for preventing corrosion on screw threads as it may even make the effect worse. Perhaps somebody on the list who is more expert on the chemistry could comment. Must admit however to filling the high gain UHF 8 stack antenna connection boxes on a Cable TV head end to the brim with the same petroleum jelly to prevent moisture entry in 1971 and that never ever suffered over many years in what is reputed to be the wettest area in England. (the true rainfall figure may have been inflated by small boys assisting in the collection data by adding a certain yellow colored liquid) Really all of this is academic as the biggest cause of non conductivity with the chassis screws must be the coating on the outside of the case panels. This must be quite a good insulator and no way would I for one want to try removing it to ensure a good metallic contact. The inside of the case is a different matter and consequently with case bonding the connectivity must rely on pressure between the inner of the case and the chassis 2D fastener, not the screw thread directly. The problems that come up with trashing the Phillips screw head is usually made worse by using the wrong type of Phillips driver. There must be a wide variety of types internationally to compound the issue. In the UK we seem to have two types. The earlier Phillips British type which still appears in instrument screws and has a quite sharp pointed shallow angle tip. The current usage is with what is referred to as the "Posidriv" type which has an almost square end with a slight dome on the tip and has a much wider angle on the tip blades. Equivalent screws to this are used commonly on Japanese equipment and are marked with a single dot on the screw head. Using one of the earlier Phillips drivers on these screws is a recipe for disaster. With the Stanley drivers we buy here, the Phillips has a red plastic handle and the Posidriv has a blue one to easily identify the type. The K2 case screws seem to fit my Phillips British type driver better and even using a small Posidriv driver with a no.1 point would soon trash the heads due to the poor fit. May be different with Phillips drivers available in other countries. Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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