Can someone tell me what the metric size is of the two different bolts that are used on the Strombergs. I don't have a metric pitch guage and the helper at the local hardware store was of little help.
What I do in cases like this is bring the bolts to the hardware store and paw though the bins til I find a nut that matches, then you know the bolt thread pitch....
Keep in mind there is such thing as a # 12 bolt. ( most hardware stores only stock 6-8 and 10s) They are There are two of them in a holley 94. They will drive you crazy if you dont know what you are looking for which may make you think they are metric... Maybe the stromberg is the same i dont know.
The 48's, 81's, and 97's have no bolts in them. They do however have 10/24 and 1/4-20 Fillister head screws. The Holley 94's have the 12/24 screws as well as the 1/4-28, and 10/32 fillister head screws, again not bolts. There are a bunch of "oddball" Strombergs out there but all the ones I have ever fondled have American thread pitches.
I have always been told by the "older guys" that the Holley 94 as well as the 97's,48's and the 81's had metric screws. I never questioned it so now I am enlightened. I will check these just to be certain that they are standard. Thanks for the responces.
****ster27, post #7 above, has it exactly right. Bolts? No. Screws? Yes. Some are not very common thread pitch. Do a bit of research before you destroy threads in the carb(s). Also, just because someone is one of the "older guys" does not mean they know what they are talking about. Age does not the standard for knowledge.
Normally, when one refers to "Stromberg" on this forum, one is referring to Stromberg USA. However, there were also Strombergs produced in other countries, some of which indeed did use metric pitch threads. While I am unaware of any metric pitch used by Stromberg USA, that is not a statement that metric was not used in some obscure application. When one asks such a question, one might supply a carburetor type in the question. Examples: Stromberg USA - models EE-1 (some of which were called "97") Stromberg UK - DAA-42 Most carburetors use fine threads (or non-standard even finer than fine) for the extra holding strength. And as mentioned by ****ster, the heads on most of the machine screws will be the heavier Fillister type. Other types were used in some applications. To really muddy the waters, some of the non-USA Strombergs used Stromberg USA-parts! Further, some of the more exotic non-USA makes used Stromberg USA carbs built in the USA, exported to a different country, and then modified. An example of this would be the AAV-26(M) sold by Stromberg USA to the London Branch where they were modified for use on Rolls Royce. Jon.
OK - just for grins I just leafed through the Bendix - Stromberg Engineering Standards sections on bolts (yes, bolts are specified on some carburetors), screws, and nuts. There is no reference for metric thread in the book. Latest update 6 February 1968. This reference cites the S.A.E. handbook as the authority for thread sizes and tolerances. Jon.
here is no universally accepted distinction between a screw and a bolt. The Machinery's Handbook describes the distinction as follows: A bolt is an externally threaded fastener designed for insertion through holes in ***embled parts, and is normally intended to be tightened or released by torquing a nut. A screw is an externally threaded fastener capable of being inserted into holes in ***embled parts, of mating with a preformed internal thread or forming its own thread, and of being tightened or released by torquing the head. An externally threaded fastener which is prevented from being turned during ***embly and which can be tightened or released only by torquing a nut is a bolt. (Example: round head bolts, track bolts, plow bolts.) An externally threaded fastener that has thread form which prohibits ***embly with a nut having a straight thread of multiple pitch length is a screw. (Example: wood screws, tapping screws.)[2] This distinction is consistent with ASME B18.2.1 and some dictionary definitions for screw[3][4] and bolt.[5][6][7] The issue of what is a screw and what is a bolt is not completely resolved with Machinery's Handbook distinction, however, because of confounding terms, the ambiguous nature of some parts of the distinction, and usage variations.
The Stromberg screws, (bolts), can be used with nuts, so according to the above that would make it a bolt???????????????????????????????? I just know that they aren't metric.. The End... Duane.
I was taught years ago a bolt incorporates a smooth shank as part of its construction whereas a screw is threaded all the way along its length. This is within the automotive world as distinct from the carpentry world where a wood screw may well have a smooth shank incorporated. Confusing aint it!
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