I'm trying to find out what size of carriage bolt holds the wood firewall to the frame on my 16 Coupelet. I'm not talking about the firewall brackets.
I know the nut is brass if I remember correctly but I don't remember the size of the bolt. This attaches through the steel hood former and through the wood firewall.
Look on Lang's website but couldn't find the correct one's.
Philip Berg:
They are 5/16" with a VERY LARGE HEAD. My 16 has steel nuts.
What happened to the original bolts that you removed when you took off the hood former and firewall? I can see the passenger side bolt in this photo:
Here is an interior of another unrestored 1916 coupelet. It is about six months newer than yours, based on the motor number. The nut appears to be steel, not brass.
I still have them but I'd like to replace with new ones if I could. The shanks have started to rust and have caused thinning of the bolt diameter. My car is 120 miles away so I cannot go out to the garage and look. I plan to go up to work on it Thanksgiving week and would like to order a replacement sent this week if possible.
The nuts may be steel my memory isn't what is use to be
I believe it is this bolt, if so I have quite a few n.o.s., Bob
Philip -- Bob beat me to it. I was going to tell you that he has some NOS ones. I bought a few a while back to have in stock. It's my understanding that they used brass nuts on them.
About the nuts -- The '15 cars I have seen had brass nuts on those same bolts. But Ford may have changed to steel nuts for the 16's, since they were reducing the amount of brass used in the cars. Dave and Erik have been paying attention to this stuff for a long time; I'd tend to take their word for it.
I am in no way an expert so don't take my comments as gospel.
These are known as "Step Bolts" and at one time you could walk into Orchard Supply Hardware and buy them from the bin (not "off the shelf!"). Nowadays, NADA! I believe the name came from using them to bolt down wooden stair treads to metal risers. The wide head provided better "crush" against the wood, and the shallow head was less of a trip hazard. Another similar headed bolt was the Elevator or Plow bolt, but the top of that head is flat, and the bottom side is slightly tapered. Nowadays some folks confuse these types of bolts for each other, or mistakenly think they are the same.
Yeah, I know hardware trivia. . . .
T'
David D.
David -- Thanks for that bit of trivia. I never know (and wondered) why they were called step bolts. Now I know. (I think.)
Restoration Supply has them. 5/16 X 20 "Step Bolt" Head dia 1.023 or "Flush Head Bolt" Head Dia 1.210. www.restorationstuff.com
OK for those of us addicted to "minutia" here is something to look at in the picture above. Look very carefully at the threaded end of the 2 step bolts that are in Bob's picture. Early fasteners all had a standard finish on the ends that was to ROUND the end off and not cut it off square. The smaller the bolt the more noticeable this was because the standard way they specified it was typically 1/32" rounding off or 1/16" rounding off. Modern bolts have the threaded ends square cut or in some cases when the threads are rolled, there is in fact a small cup at the end of the threads with the thread thus having a slightly hollowed end. A good show car judge looks at threaded fasteners on brass era cars and can spot most modern hardware that way. I make the running board truss rods for the T (and of course have the drawings for them) and the ends of those rods were rounded this way when they were made during the T era. A replaced or fabricated truss rod that is modern is easy to spot by simply looking at the end of the rod. Of course being totally anal I have the correct roundness to the ends of the rods that I make and while supplies are lasting I also have the correct single chamfer washer faced nuts supplied with them. Those will not be supplied with the truss rods I make once our supply of them is exhausted but we have preserved them to supply them on our truss rods so don't worry. Most modern carriage bolts and step bolts have a slightly smaller diameter head than their earlier counterpart. Early 1/4" carriage bolts had a 5/8" diameter head while modern 1/4" carriage bolts typically have a 9/16" diameter head.
Ok since we are talking fasteners here what type of screw should I use for the bottom holes? I don't think there were any screws in them when I removed the hood former.
To add to my original comment - if you have the original bolts, clean them on a wire wheel and re-use them. I can't believe that the shanks are so rusty that a substantial amount of diameter has been lost. If they were that extremely rusty, I would think the rest of the car would be so rusty that all the sheet metal would look like lace curtain.
Your coupelet deserves better than modern bolts off the shelf. If the original bolts are beyond use, get genuine replacements.