The Stovebolt Site Forums The Shop Area General Truck Talk Internal Tooth vs External Tooth Lock Washers

Does anyone know the correct application of external tooth and internal tooth lock washers? There's a number of different styles, internal, external, internal/external, twisted tooth, flat tooth, etc. I find these 'star washers' from time to time on the '47. Often, they are rusty and break into pieces when they're removed, like the ones on the side vent of my truck. I'm just wondering if they were meant to be there or if that's the only lock washer that was available during a previous repair........

Thanks!

This might help. https://www.homedepot.com/c/ah/how-to-use-a-lock-washer/9ba683603be9fa5395fab9014e68c0b0

When these trucks were built, there was no reason for GM to imagine that these trucks would still be around and on the road 60+ years later. In fact, I am sure that they hoped that these trucks would be replaced fairly frequently.
The type of washer of which you speak worked fabulously for the time period which a reasonable person would expect a work truck to last.
Those star washers hold better than the more durable, longer lasting simple split washer in several places on these trucks. The side vent must be able to take the brunt of stiff wind resistance while barreling down the road at breakneck speeds, exceeding 50 MPH at times.
I find enjoyment contemplating many of the aspects of the components and their design as to why it was designed that way. Very seldom does one find an instance where something does not make any sense. Sure, there were changes made in later years to improve components, but at any given time, there was sound reason behind why they did things the way they did at that time.
And indeed, there where later "improvements" which were not improvements at all. They likely came from cost saving incentives, or drunkard engineers with a long leash.
Carl

The star washers work good for mounting electrical components on newly painted areas, as the sharp points will grip through the paint for a good ground.

Works well on paint not so well on powder coating.

Thanks for the feedback. It is interesting to muse a bit about the design and functionality of these old trucks. Generally speaking, the hardware and components have withstood the test of time in an impressive fashion over the last 70 plus years. I only hope I can function that well at that milestone! There's certainly a lot satisfaction derived from keeping 'em on the road. I don't recall what Stovebolter used to say this, but the old adage of 'Do no harm' seems appropriate as well...........

I believe that man was Dr. Elias P Stovebolt. The good doctor simply applied his Hippocratic Oath to his hobby...

Ah yes, the good doctor........

Thanks for clearing that up!

Here is a company that specializes in bolt/washer "science".


Here is their entry/wisdom regarding helical spring lock washers.

We rely on personal experience and interesting/entertaining postulation/examples and sincere/reliable bs.

Which should we believe/trust?

Let's start with images for:
internal tooth,
external tooth,
internal-tooth/external-tooth,
twisted tooth,
flat tooth, and
"star washers"
(please post/attach and clearly label/identify them)

To the best of my knowledge/experiences/inability, I will simply/lamely/numbly use what Chevrolet/GM used "in the day".

Just look at the FAM. They used mostly split tooth lock washers then as they do now. You will see a few star washers. They also used special countersunk toothed washers on flathead and oval head screws.

To add to the mix, there are also conical external and internal tooth lock washers. I recall finding a couple of them at the front hood to lock panel brace.

Has your head exploded yet Tim?

[on edit] Looks like bartamos beat me to the punch on the conical washers for flat head applications.

Yes, Kevin, you have caused my head to explode - Thanks.
internal and external conical toothed serrated lock washers

I'm getting to the same point. I had no idea there were that many variations, as shown in your last link.

Then you have the '47.1 through '55.1 GMC trucks. They had toothed washers under the bolts which held the fenders to the inner fenders.
Chevrolet didn't use any lock washers there.

52 Carl, When I taught at GWU, a product quality class was part of the Curriculum. A transcript was available from GM Chevrolet division in late 1952. The board members were concerned that the sales of their advance design trucks was showing a drop. It was determined that most farms kept the design to long because it did not rust out. At this same meeting they decided to phase in the mid 55 design. As all of us that have had a tri 5 and later we knew that the doors held water and would rust out fast. Oldsmobile division also had an abundance of one piece wind shields thus the one piece design on 54 and 55.1. The owners found the previous advance design trucks were easy to work on the mechanical plus the cabs lasted too long. If a person keeps the cab corners and doors cleaned out any moisture will pass out the drains. All my 55's up through my 66's had large amounts of rust ( Florida trucks),except the two from Arizona. During the transition the steel formula was also changed. I must admit that until the 265/283's engines were introduced the old stovebolts were easier to work on. I love them all. Planned obsolescence became part of all of the big 3 vernacular Doc.

Yes - planned obsolescence - a Tri-Five (and later) designed-in attribute:

"Obsolescence is the state of being which occurs when an object, service, or practice is no longer wanted even though it may still be in good working order.

The international standard EN62402 Obsolescence Management - Application Guide defines obsolescence as being the "transition from availability of products by the original manufacturer or supplier to unavailability".

Obsolescence frequently occurs because a replacement has become available that has, in sum, more advantages compared to the disadvantages incurred by maintaining or repairing the original."

Bet you didn't know there is an International Standard on Obsolescence?