Wednesday, January 6, 2016

Clutch-head screwdrivers

Above, one of my Upson Brothers (of Rochester, New York) clutch-head screwdrivers.  I also have a set made by Herbrand (of Freemont, Ohio) and several Forsberg (of Bridgeport, Connecticut) "Whale" versions.

In 1933, Joseph F. Fieg was assigned a U.S. patent for a screw head of his invention, which he assigned assigned to the United Screw & Bolt Corporation of Cleveland, Ohio.  In his patent application, he argued that the form of the socket acted like a clutch when engaged with a flat-head screwdriver, hence "clutch head."  (See 1939 patent drawing below.  Personally, I think the comparison to a clutch is a bit of a stretch.) In the initial patent, he also recommended that the head of the screw be made hexagonal so it could also be turned with a wrench.  This type of screwhead was marketed by the company as "Type G", resembling a butterfly.   As a result, it was often colloquially referred to as a "butterfly" or "figure 8" screw.

It was commonly found on recreational vehicles, mobile homes and some electrical appliances manufactured into the late 1970's.

Mervin J. McGuffin.  Automotive Mechanics.  Principles and Operation.  The Macmillan Company of Canada Limited, 1962.

In 1940 , Fieg patented an improved version which incorporated a cylindrical opening in the centre of the socket to better locate the specialized bit.  This version resembled a bow tie and became known as a "Type A."  (I've no idea why a later design would receive a lower alphabetic designation, but there you have it.)  It was also referred to as a "clutch type" or "clutch tip."

Tools and Their Uses.  Prepared by the U.S. Navy (Bureau of Naval Personnel).  Dover Publications, Inc., 1971, 1973.

William Toboldt & Jud Purvis (Editors).  Motor Service's Automotive Encyclopedia.  The Goodheart-Willcox Co., Inc., 1965.
Because of the very positive engagement between driver and screw, it was well suited to mass production and was adopted by Chevrolet for their cars, trucks and buses from the 1940's through the 1950's.  As a result, it was sometimes referred to as  a "Chevrolet screw." It could also be found on older tractors, where it was used to secure sheet metal parts. (In contrast, General Motors adopted the Phillips screw, patented in 1936, first on the 1936 Cadillac and later for their trucks.)

Clutch head screws came in six sizes, based on the largest diameter of the tip.  For more on this, go to

The fastener never seems to have caught on more widely.  For example, according to Tools and Their Uses, prepared by the U.S. Navy (Bureau of Naval Personnel in 1971:

"Recessed screws are now available in various shapes.  That have a cavity formed in the head and require a specially shaped screwdriver. The clutch tip is one shape, but the more common include the Phillips, Read and Prince, and newer Torq-Set types. The most common type found is the Phillips head screw."

Clutch head screws had pretty much fallen out of use by the mid-1970's.  For example, in their 1977 catalogue, Herbrand Tools no longer offered this type of screwdriver.  Even though it provided much more positive engagement and far less cam-out than the Phillips screw type, Phillips managed to prevail in spite of its known limitations.  For example, as early as 1945 even GM acknowledged the cam-out problems of the Phllips screw:

GM's ABC of Hand Tools.  Their Correct Usage and Care.  (General Motors Corporation, 1945).

Evidently, "the screw that sells itself" didn't.  (The same applies to the older, Canadian Robertson recessed screw types, which have much better driving qualities than Phillips, yet failed to get much market penetration south of the Canadian border.  I'll take a Robertson over a Phillips any day.)

As for the parent company that made clutch head screws, it's gone now.  United Screw and Bolt was sold to Plastech Engineered Products, Inc. for $128 million in 1997 in a deal brokered by the Ford Motor Company. Founded by Julie N. Brown, Plastech was for a while the largest, woman-owned company in Michigan.   In 2006, the firm had $1.1 billion in revenues, but by 2007 that had been replaced by $100 million in liabilities, even following a a $46 million bailout by Ford Motor Co., General Motors Corp., Chrysler, and Johnson Controls inc.  Following a dispute with Chrysler, its fourth-largest customer, the company filed for bankruptcy protection in 2008 and was ultimately bought by Johnson Controls.  As we all know, both Chrysler and General Motors filed for bankruptcy protection a year later, in 2009, and were only saved by huge taxpayer bailouts.  United Screw's demise was just collateral damage.

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