Thread: Discussion: Why do we use pivot washers?

Originally Posted by Philadelph

As for the thickness of old washers, I don't think 'wear' makes them seem thinner. The washers people get from microfasteners (or similar) to generally use as this type of washer are about .017" if I recall. I haven't seen any vintage razor with washers that thick- most all are around .005" or less. Also, if the thin washers were only thin because they are worn, then there would be too much space between the scale and blade (material lost) and the blade would be loose. This isn't usually the case (in my experience). The washers would also only wear to the point of the scales being loose and then not wear anymore. I just think they used thinner washers for a reason, but I'm still not sure what that reason is. I prefer them aesthetically and think they give a razor a better opening/closing action than thicker washers do- but that's just me.

Nope. It's not just you. tight fit looks good.
I see your point, and even though it is old doesn't mean it was used for an especially long time

Just thinking out loud here but the function of a washer under the head of a bolt or screw is to protect the material from the edges of the bolt/screw head and to distribute the load to a wider surface area. When we tighten the pin on a razor pivot with no washer the pressure is applied wherever the tang and scale are in contact. With washers the load is limited to the area of contact between the washers, scales and tang. I think that is a better situation, or maybe it doesn't make a dime's worth of difference ?

Well as far as i understand it...

The pivot is a movable joint between hard and a soft material. For the joint to be reliable (tight) there must be another material of medium hardness placed between them as a buffer, if not then the hard material will abrade the soft material in short order… I am sure some of us have used “plastic” (nylon) bearings (washers) instead of brass, only to discover they didn’t last long because we substituted one soft material for another.

Very old razors with horn scales did not have bearings (washers) because that mechanical technology did not progress to the manufacturing of razors at that time. But to keep the razor tight in the scales, the old guys roughened the insides of the scales at the pivot... I have see the same done to some Ivory and Bone scales too.

Originally Posted by kevint

I don't think the washer can help centering on an oversize tang pivot hole-it would have to be attached to the tang. Nor reduce wear as I dont feel the scale material will care much whether it rubs on brass or steel.

The washers I have seen that are cupped in the middle have a small hole the size of the pin in the centre, so the washers are effectively locked in position cntre-to-centre by the pivot pin, which is held in position by the tight holes in the scales, which in turn are fixed in relation to each other at the wedge end. The oversized hole was then taken up by the opposing cups or bosses in the centre of each washer, effectively turning it about a fixed point - centering it was probably not the best word to use. The last set of washers I saw like this came from a circa 1950s razor and were made of strong sprung steel with a blued finish and were obviously made to do a particular job. I have only seen two or three examples and I kept the washers, preferring to bush the pivot hole with brass tube.

The 'wear' I meant was not at the exact location of the washer, but at the junction of any flared/projecting part of the tang and scale material - by adding clearance.

Like Alex, I don't find the modern use of thick washers particularly attractive. The old ones - from Sheffield, anyway - were made from an extremely thin brass-type alloy called 'latten' (the word itself means 'thin' and comes from the german 'latte' meaning 'slat') - the stuff they used was made even thinner than usual by hammering or rolling.

A small bonus - though I am not for one second suggesting that this is why they were used - is that the copper content of the latten makes it germicidal to some degree - they say that brass doorknobs effectively kill most germs on them in about 8 hours!

I have seen those rasp marks that Smythe mentions, but always thought that they were just last-minute alterations to the inside of the scale to make the blade centre properly, but Smythe might be onto something there as I also find them at the wedge end of old and not so old razors - they certainly help in holding an unglued wedge in place, and all the wedges seem to be used without glue.

Regards,
Neil

All right! I'm learning stuff now!

I've only taken apart about 15 razors, with about 10 being Sheffield blades and have found that with the Sheffield razors only 2 or 3 had the washers. However, all of the solingen razors I've done(5 I think) have used them. Of course I'm sure you guys have done much more restorations than I have, so I don't mean to use this as a point for disagreement, just an observation. When I use them on razors that did not have them originally I find the blade does not pivot as easily, almost like the washer adds friction to the blade.

Just to jump in here, I think it's the clearance that the slight thickness of the washers provide. In particular, the shoulder/stabilizers could hit on the inside of scales without enough flex. It's really frustrating, and adding a washer bows out the scales just enough (sometimes) to fit. If Glen or Neil or someone went back and actually counted the percentage of washer occurrences, I'd be interested in the thickness of the tang and shoulder design as well. Anyone up for a research project?

Without multi-quoting the whole thread...

I don't know the percentage of "washered" razors I've seen, but they are usually much thinner than the washers I have on hand. I would agree with Alex that it's almost certainly not a function of wear. As Neil said, they just used really thin stuff. I hammer my washers from microfasteners.com or clean and reuse the originals.

I think water gets trapped in between the washer and tang just as easily, if not more, than between scales and the tang without a washer. However, there is a smaller surface area in contact between a washer and tang than in left alone. (Depending the on flex of the material when closed, a lot of the tang could be contacting the inside of the scales.) Could be a benefit to a washer.

As for wear, Neil pointed out the little divot or taper in a lot of washers, which lends me to believe that washer is still spinning and rubbing against the material of the scales. What it does, I don't know. Want to know the result? Look inside an old set of scales with washers and see if there's a circular grove.

Although all the previous posts had some real merit to them, I believe I know the answer. It was all started some years ago when a group of industrious washer manufacturers planted the seed that it is imperative they be used at the pivot pin knowing that you'd lose at least 2 or 3 in the process which would in turn make you buy more washers. Pretty that's why.

One thing just occurred to me that may have some merit. If it wasn't worth the cost of the material and labor they wouldn't have used them. Keep in mind that individuals made up those companies and those individuals who lived through the great depression didn't waste anything. Sort of like what some of us learned during the recession in the early '70s, precipitated by the Arab oil embargo, and other younger folks are beginning to learn now.

Jimmy that was probably the most intelligent observation of this whole thread.... have a beer...