I am close to re-assembly of my 1937 Lasalle Opera coupe and decided to mount mirrors using modified door hinge pins. I'll be making longer pins to hold the mirrors and not sure what material to make the pins. My guess is stainless would work and possibly 4140 steel but not sure so thought it best to ask the group and hopefully find a machinist who can give me some guidance. I did order some new pins which won't work as they are far too short, but wanted to measure them and compare to the old ones. Surprisingly, the old pins have not shown any wear at all. Here's a couple of photos depicting the way I got the car back (it's the same vehicle I drove through college in the 60's) and one in its current state, just about ready for paint.
An engineer would make them soft, so as to be the wear part, and not ruin the more expensive and harder to replace hinge brackets. Cheap bolts from the hardware store skillfully ground and polished would be my choice. Got a lathe? Keep in mind, too tight is always a bad thing in building, and, you won't live long enough to wear out chinese bolts. And...I'm not an engineer
Hit the old ones with a file to see how hard they are. Use the corner of the file. If it digs in, modify a grade-5 bolt. Or the 4140 steel will be good. If the file skates off, go with something harder, as in a grade-8 bolt to modify. Ace Hardware by me has some A286 stainless steel bolts.
Its not HAMB friendly, but Henry Richards, that originally built the '39 Standard that Jesse James owns, used quick release pins, commonly found in drag racing. I'm not sure of the material, but I doubt it is anything exotic, like H13 with some crazy hardness.
Drill blanks... drill blanks | McMaster-Carr Available in all drill sizes (letter, number and fractional, even some metric), you'll have no issues finding the size you need. Less than $20 for three foot lengths in any size under 1/2". You can get up to six foot lengths. This listing is easy-to-machine steel. You can also get various hardened steels.
how do you attach the rounded end to the drill blank? perhaps make one that presses on? I'd be looking at the required dimensions first, then how to make them, and worry about material last. As long as it's some form of steel, it will last as long as it needs to. Especially if you remember to oil the bushings once or twice in the future.
If there's no wear on the pins, is there wear in the hinges? BTW, the shaft of cheap bolts is not usually truly round.
This discussion about pins reminds me of a place I worked at some years back. One of the weaving machines wouldn't take up the fill; when I went to fix it, I discovered that the pivot pin had gone missing from the fill takeup jaws, and someone just stuck a screw in its place to fix it. Didn't take long for that arrangement to wear things out!
Weld a nut or flange on the end then chuck it into a drill/lathe and grind/sand to shape. If you make the hinge pin stationary and use a sleeve in the middle of the hinge, the bearing area will probably never wear out...
For a quality, easily machined, higher strength, heat treatable if needed, relatively inexpensive steel, round stock for lathe work. My go to has been 1144 stressproof. But it's generally not considered weldable, fyi. If that's a quality you need. But, if you already have some 41XX / 43XX in stock there's no real reason not to use it.
Drill blanks will work for straight pins but are hard and don't have a head on them. My suggestion is to look for a similar length pin for a later model car that has slip on bushings around the pin for wear. If you need longer ones, then I'd use a stainless steel rod. Stainless won't rust later and still has good wear resistance. You can solder or braze a head on it pretty easily. Just saw a two pack of 5/16 x 12" for $20 on Ebay with free shipping. As I said, you might want to look for ready made bushings that fit your doors and then buy a rod size that is a slip fit into them. Two 12" pieces ought to be more than enough. I fixed a hinge on a late 80s Camaro once, and since it had such a large door I decided to drill the hole out larger so I could use a bigger pin in it because of wear. Then I had a long stainless bolt laying around and used it for my pin with some bushings that adapted the sizes I needed. Worked fine and stronger than ever. Stainless bolts will work and you can turn the head round ...if you can find long enough ones for your needs.
Take one of the old pins to Home Depot or Lowe’s - they have a specialty fastener section with pull out stacked drawers. If you can’t find it there - go to a full size Ace or specialty hardware supply store - this may take a few hours but I have been able to source alternative hardware that is obsolete doing this. Jim
Among numerous other things, I fabricate/reproduce & sell door hinge pin sets (see attached picture), including the pins (both in standard & oversized) with multi-piece (brass) grease fittings for a certain 50+ y.o. vintage Italian sports cars and have found O1 Tool Steel most ideal material for pins (available from McMaster-Carr, for example) Drill blanks, IMO, are far too hard if any machining is required. YMMV.
Almost anything will work. Drill blanks are usually Vega-ish tool steel. I would look fie the on-the-money stock size material. Just cut it to length. 303 or 304 stainless is abundant in round stock and is plenty tough.
While I (sort of) agree, I would add that proper maintenance, i.e. periodical cleaning & lubrication are the key for good service & longevity. For example, the now over 93 y.o. original pins of the (original) hidden door hinges in my PB Roadster are quite small (read fragile), have traveled over 100K in last 35 year and who knows how many before me. I’ve serviced (= lubed) them periodically, but will probably need to make all new hinges, incl. pins, etc, sometime in the next 30 years.
Help card at the auto store have them for various car and trucks. I’d measure them. Easy to cut off if correct dia.
I've been using Drill Rod for as long as I can remember. I tig weld a S.S. nut of necessary size after drilling out the threads to drill rod size on the top end and turn to a crown as needed and polish them, cut to final length and move on. Never have done a second repair on any I've done that way.
I was just about to suggest this. Just yesterday I was at NAPA getting a universal shifter linkage bushing kit they had and I saw a universal door hinge pin kit with super long pins. Nice head on one end, a little spline on the lower end to lock it into place. I think they were Dorman products. If they happen to be the right diameter and length (or close enough to trim to fit) that'd knock right in there really easily. The universal bushing kit was perfect for my dad's GMC shifter, took all the slop out of the very worn system. Had to cut them down/redrill them a bit but with fairly minimal effort they worked perfectly. There's a surprising amount of useful stuff for old cars in the parts stores yet.
If the pin diameter is a nominal inch fraction diameter (or Metric) you could use industrial Shoulder Screws. Older hinges usually need a freshen up so a larger nominal diameter may be suitable and the hinge can be accurately reamed to suit. The screws have an accurate cylindrically ground diameter and are typically made from grade 8 steel. The heads shape can be modified if needed and also have a flat machined to control rotation in the hinge body. There's lots of different ways to make them work ..... good luck with it. https://www.mcmaster.com/products/shoulder-bolts/shoulder-screws-2~/alloy-steel-shoulder-screws-9/ https://www.mcmaster.com/products/s...screws-2~/metric-alloy-steel-shoulder-screws/
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