GregLaR

Number 12 Screws, Aaarrgh!

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They are practically non-existant today,  but my '38 is loaded with them! Also #8's & #10's which are still pretty easy to get at any hardware store.  The 12's proved pretty difficult but then I came across a good guy at the local True Value Hardware store. I told him my dilemma and he said he stocks a couple cases of number 12 coarse thread screws both in countersunk and cap heads in various lengths.

Guess why he stocks them? For guys with cars from the 1930's! I love this guy! B)

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Amazon also has lots of #12s. I use them to replace #10s in thin material.

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Wait until you need number 14 or number 16 machine screws. Yes, there did used to be such things. If I recall correctly, a number 12 is slightly smaller than a common quarter inch, while a number 14 is slightly larger, coupled with the numbered screws having a different thread pitch (count). A number 16 is slightly larger yet.

Of course, one could always get into really old stuff, even early automobiles, but especially carriages and old machinery from the mid and late 1800s. Machine screws were originally made in matching lots and even individual pairs by machine shops and local blacksmith shops, each with their own preferences for sizing, and thread counts. The first solid efforts at standardization were in the early years of the 20th century. Henry Ford was one of the leading businessmen pushing for standardization because he was trying to buy parts and special order manufacturing from numerous suppliers (Wilson bodies and Dodge Brothers machine shop were only two of many). He wanted to be able to assemble his early cars quickly and efficiently without hassling with bolts that did not fit. He set very strict standards for his purchases, and the early SAE (Society of Automotive Engineers) followed suit copying some of Henry's specifications, and making many of their own. The SAE was founded in 1905. Prior to that, sizes were pretty much anything goes, and their influence did not become widely accepted until about 1910. Many high wheel automobiles used non-standard nuts and bolts following the practices they had been using in the carriage industry for decades before.

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Most of these odd sizes are available from serious commercia; fastener companies; because they are not popular so most retail stores don't carry them

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I had to laugh at the topic. I made a pit stop at a Sheetz convenient store on the way back from Hershey. That was written on the men's room wall. I made an extra pass through the store checking out name tags.

Bernie

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I am trying to remember the size14 that we ran into on the 31 Dodge.

So, close to 1/4 but that thin red hair smaller.

One of my old tap sets has a # 14 so I could clean the threads. I cant remember where we (the owner) found the actual screws but they must be out there.

It just goes to show, its always something !!

 

Having fun yet ?

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Fastenal also has a good selection of screws and related items.  They're a nationwide chain so there is probably one near you.

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Does anyone know if it is possible to buy wood screws with a larger head diameter? Say like 8's with a 10 diameter head?

 

Howard Dennis

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As Joe states, McMaster-Carr has any size bolt, screw and nut you need. They are a lot cheaper than most hardware stores.

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6 hours ago, 46 woodie said:

As Joe states, McMaster-Carr has any size bolt, screw and nut you need. They are a lot cheaper than most hardware stores.

 

Not only that but McMaster charges ONLY ACTUAL shipping.

No handling or extra fees!........ :D

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6 hours ago, cahartley said:

 

Not only that but McMaster charges ONLY ACTUAL shipping.

No handling or extra fees!........ :D

 

That's new.  Remember ordering a part that could have been put in an envelope for 48cents, but it was put in a box and charged like $15.00

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We probably order from McMaster Carr once a week on average. If we place an order by 5 pm we have the items by 11 the next morning. They actually have a UPS shipping station inside their warehouse, We couldn't live without them. Here's a secret tip. If you need an odd sized screw or whatever that they don't list in their catalog they will do a search and if the product is available anywhere they will find it and sell it to you. We have used this service many times to find odd sized fasteners. It's a bit tough to get their 4000 page printed catalog but once you are a regular customer and know the secret hand shake they will send a new catalog every year. Happily the catalog is now online for you younger folks who don't know the joy of actually holding a huge catalog in your hands like those of us who grew up with the Sears "wish book".

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17 hours ago, Harold said:

Fastenal also has a good selection of screws and related items.  They're a nationwide chain so there is probably one near you.

From the Fastenal near me, I bought replacement cylinder head hex nuts that were marked as the correct inch-dimensional size--and also marked "made in China"--but fit too loosely on the studs for proper torqueing.  US-made nuts from another source fit perfectly,  Never again... 

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Interesting topic, and one we have issues with almost daily.

 

Machine screws, especially Fillister head as used on carburetors, in sizes 4-36, 6-40, 12-28, and 1/4-24 are almost impossible to find. We have actually had a machine shop cut several of these by the thousand. To compound the issue, many of the screws even found are stainless steel; which should NEVER be used on carburetors.

 

Jon.

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They are too hard. OK to use on cast iron, but will pull the threads on zinc (pot metal) castings. Have not tried, but would not want to use them on brass either. Lots of carb castings do not have sufficient "meat" to install a heli-coil or go to the next larger size. Easy to ruin a casting.

 

Of course, should one ignore this advice, I know an old hill-billy in Missouri with literally tons of carburetors for sale! :D:P

Jon.

Edited by carbking (see edit history)

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HA !!

You gotta love those hill-billy hoarders.

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7 hours ago, Larry Schramm said:

 

That's new.  Remember ordering a part that could have been put in an envelope for 48cents, but it was put in a box and charged like $15.00

It's nothing new.

We've been doing business with McMaster for many years.

We've never been charged anything over actual shipping.

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1 hour ago, cahartley said:

It's nothing new.

We've been doing business with McMaster for many years.

We've never been charged anything over actual shipping.

 

I guess define "actual shipping"  It is what it is.

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If it costs $3.69 to send something that's what's charged.

If it's something they had to order in then we pay their third party charges plus theirs unless it's something that can drop shipped in which case we pay that charge only.

 

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Actual shipping means "whatever it took to ship the part" when the guy boxed it.  When I am trying to get a quote for others to purchase from McMaster Carr, I can not get a shipping quote online in my shopping cart. So we have to tell the customer "I think it might be around this price"...:o

 

I am still amazed at the number of people here who buy a 10 foot length of pipe from McMaster Carr that could be picked up local from a hardware store or plumbing supply house with no shipping charge. Has to go truck freight, of course, from McMaster. :(

 

Stainless steel machine screws have  about the same Rockwell B range  as regular steel,  maybe slightly harder (B-75  to B-85 depending on source and size). Tensile strength about the same also in machine screws. They do look good on my carburetors! GM used them on the Corvair YH carburetors from the factory. OK, maybe they were chrome plated steel...??;)

 

I do agree there is not much meat to Helicoil  most carburetor screw holes. Zinc casting not forgiving. Good warning!

 

Delco generators used 12-24  threaded studs for the Armature and Field terminals for years, until they went to alternators in OEM production (then 1/4-20 on the alternator terminal). I run into them other places as well.

 

 

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2 hours ago, Frank DuVal said:

Stainless steel machine screws have  about the same Rockwell B range  as regular steel,  maybe slightly harder (B-75  to B-85 depending on source and size). Tensile strength about the same also in machine screws.

 

Seems to me stainless is much harder to drill through than regular mild steel. Also I seem to recall stainless has a rougher surface, so possibly in an application were they are installed and removed repeatedly like a carburetor they may cause more wear on the threads of the casting. I took material science a very long time ago. Stainless steel was barely mentioned.

 

8 hours ago, carbking said:

They are too hard. OK to use on cast iron, but will pull the threads on zinc (pot metal) castings.

 

 

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