Tue Jan 27, 2009 2:30 pm
Tue Jan 27, 2009 3:06 pm
Tue Jan 27, 2009 4:34 pm
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Wed Jan 28, 2009 4:08 pm
Thu Jan 29, 2009 7:34 pm
Thu Jan 29, 2009 7:57 pm
mtpopejoy wrote:...
The plywood flooring in the back is screwed down to cross braces with a million STANDARD HEAD screws.![]()
The front steel floor is held down with STANDARD HEAD bolts with square nuts behind them.
Weren't phillips head screws available back then??? Jeez!!!...
Cross-head, cross-point, or cruciform
has a "+"-shaped slot and is driven by a cross-head screwdriver, designed originally for use with mechanical screwing machines. There are five types:
Phillips
Has slightly rounded corners in the tool recess, and was designed so the driver will slip out, or cam out, under high torque to prevent over-tightening. The Phillips Screw Company was founded in Oregon in 1933 by Henry F. Phillips, who bought the design from J. P. Thompson. Phillips was unable to manufacture the design, so he passed the patent to the American Screw Company, who was the first to manufacture it.
Reed & Prince or Frearson
Similar to a Phillips but has a more pointed 75° V shape.[citation needed] Its advantage over the Phillips drive is that one driver or bit fits all screw sizes. It is found mainly in marine hardware and requires a special screw driver or bit to work properly. The tool recess is a perfect cross, unlike the Phillips head, which is designed to cam out. It was developed by an English inventor named Frearson in the 19th century and produced from the late 1930s to the mid-1970s by the former Reed & Prince Manufacturing Company of Worcester, Massachusetts, a company which traces its origins to Kingston, Massachusetts, in 1882, and was liquidated in 1990 with the sale of company assets. The company is now in business.
JIS
Commonly found in Japanese equipment. Looks like a Phillips screw, but is designed not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight. Heads are usually identifiable by a single dot to one side of the cross slot. The standard number is JIS B 1012:1985
French recess
also called BNAE NFL22-070 after its Bureau de Normalisation de l'Aéronautique et de l'Espace standard number.
Pozidriv
patented, similar to cross-head but designed not to slip, or cam out. It has four additional points of contact, and does not have the rounded corners that the Phillips screw drive has. Phillips screwdrivers will usually work in Pozidriv screws, but Pozidriv screwdrivers are likely to slip or tear out the screw head when used in Phillips screws. Heads are marked with crossed, single lines at 45 degrees to the cross recess, for identification. (Note that doubled lines at 45 are a different recess: a very specialised Phillips screw.) Pozidriv was jointly patented by the Phillips Screw Company and American Screw Company in the USA. Developed by GKN in the 1960s, the recess is licenced from Trifast PLC in the rest of the world.
Fri Jan 30, 2009 9:19 am
N3Njeff wrote:How bad do you guys want a Willow Run built B-24???????????
Fri Jan 30, 2009 1:31 pm
Fri Jan 30, 2009 2:16 pm
Sun Feb 08, 2009 8:09 pm
Mon Feb 09, 2009 1:04 am
Mon Feb 09, 2009 9:11 am