The difference between bone and Delrin?

[drduryea13]

Thanks to a lot of info here, I have figured out how to date my knives, but I am stuck on a few of them trying to tell if the handles are bone or Delrin. I have several that were my father's that are from the 1940 to 1964 period, trying to figure out a value etc, and I am stuck on this. Any experts here have some advice on telling the difference? I would be honored to send pictures if you are willing as well.

Thanks

[knife7knut]

Welcome to the forums! Pictures are always appreciated;encouraged;etc. One of the easiest ways to tell real bone from Delrin or any other synthetic substance is to look at it under magnification.A 10x loupe is good but as low as a 3x will suffice.Look at the ends of the scales and under magnification you will see that real bone has a porous surface whereas synthetics are usually smooth. Another way is to rub the surface briskly with a dry cloth and the synthetics will give off a noticeable odor;bone will not unless you get it really hot.It smells vastly different from any synthetic I've ever seen.

[drduryea13]

Thank you, going to experiment right now. Much appreciated.

[Phin Spencer]

Try the tooth test. Tap the scales on your tooth. If it is a dull sound likely Delrin, if it has
a ring sound it will be bone. Try it on ones that you already know and you will hear the
difference.
Phin

[zp4ja]

Thanks to a lot of info here, I have figured out how to date my knives, but I am stuck on a few of them trying to tell if the handles are bone or Delrin. I have several that were my father's that are from the 1940 to 1964 period, trying to figure out a value etc, and I am stuck on this. Any experts here have some advice on telling the difference? I would be honored to send pictures if you are willing as well.

Thanks

Welcome!

Sounds like you have some CASE XX knives based on the 40' to 64' timeframe you mentioned. The tang stamp would look like this...

CASE
XX

On the back of the knife, there may be a 4 or 5 numeric digit pattern number depending on when in that timefarme the knife was made.

If in fact you have a CASE XX knife, It will be bone since CASE only started using Delrin in the CASE XX USA in the 65' to 69' era and only on the 048 pattern if I recall correctly. In 1970' is when CASE started using Delrin on some of their patterns. Some switched to 100% made in Delrin, some used Delrin as a random substituion for bone. If you have a CASE XX with Delrin handles. that is a problem.

Sorry but not enough detail to help you further at this point. It is also possible that the knife has been reworked or modified/counterfeited. CASE knives are frequently conterfeited to make them appear older than they are based on the fact that means worth more dollars.

Please provide pics and more detail so we can help you further.

Regards, Jerry

[RobesonsRme.com]

Honestly, once one knows bone and Delrin, the difference is like that between night and day.

Like K7K stated, bone is a porous natural material that retains those attributes it had in life, cells, bood vessel channels, etc.

Delrin has none of that and is uniform in color and texture.

I'm going to post a couple of pics that might help.

These first four pics are all circa 1965 to 1970's Delrin handled knives. The first two are treated to look like "jigged" bone, a way of imitating stag.

The last two are made to look like "saw-cut" bone, a material common on Barlow pattern knives.

Look at the area closest to the metal bolster. It is uniform in color and texture and there are no bood vessels or channels in it.

These four pics of the Delrin handled knives will expand with a left click or two and you'll see how uniform and man-made they appear.

The last five knives are all bone. The first is saw-cut. Look at the lighter colored areas close to the bolster. There are little dots and other "imperfections" that are the remnants of bood channels and osseous cells.

The others are all jigged to resemble stag. Again, in the lighter areas, there are visible blood channels, etc.

Look at the last pic, which is a close-up. The details of that bone having once been living tissure are quite evident.

Charlie Noyes

[jerryd6818]

[RobesonsRme.com]

We should just delete my post altogether, as Jerry's pics are much more demonstrative than mine.
Charlie Noyes

[Shearer]

We should just delete my post altogether, as Jerry's pics are much more demonstrative than mine.
Charlie Noyes

The last picture you posted .What type of knife is it with that bolster.
Grant

[jerryd6818]

We should just delete my post altogether, as Jerry's pics are much more demonstrative than mine.
Charlie Noyes

Horse feathers. Deleting those beauties from the thread would be sacrilege.

[reddirtknives]

Any chance they used Delrin™ as a generic term for any material that is manmade like many use plastic to describe bakelite or celluloid? I know it probably doesn't really matter as far as this topic is concerned but I'm kinda bored.

[treefarmer]

Just did a search on Delrin, pretty interesting history, it has a big long chemical name and is supposed to be a very stable material, etc...Dupont's development time line seems to be in line with Case's using it as a knife scale a few years later.
Treefarmer

[reddirtknives]

Cool huh? Schrade seemed to embrace Delrin™ with open arms right from the start. What year was it that Case started using it?

[treefarmer]

Knifeaholic's book gives evidence, I believe, of 1967 as the year Case used Delrin in 100% of the 048 pattern produced.
Treefarmer

[singin46]

Actually Charlie I personally think your second pic of the Trapper shows it quite well. You can easily see in that pic that the scales are Delrin. The very even blending on each end of the handle gives it away to me anyway.

[RobesonsRme.com]

Grant, that is a Robeson made knife, but marked Paxton Gallagher, Omaha.

Robeson made several patterns of these bolster lock knives.

You can find them discussed, at length, in the Robeson Cutlery Co thread in the Knife Lore Forum.

Charlie Noyes