Are their internals the same?

General Mechanical Pencil Discussion
1

Hey guys,I purchased a TK-matic L and I really like it.

However,its internal contains plastic.

Then I decided to purchase its cheaper cousins with full-metal internals and exchange them.

Are their internals the same?

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I heard that plastic internals have shorter life span than metal ones,is that true?

I wonder whether I should spend more for just a small component.

It seems a little unwise.

4

thanks a lot

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BTW… if anyone is looking, I have an excellent Aviator for sale, no box $235 with shipping in USA

6

I was under the impression that the L had full metal internals while the others had plastic. Maybe someone switched those out on you, because they are entirely interchangeable. Perhaps someone more knowledgeable can shed some light on this topic though.

With regards to longevity, I don’t think it matters that much. The plastic internals have held up this long and a lot of people attest to the TK and Alpha-matics having some of the best automatic feed mechanisms, so not sure if it’s worth getting another one, on the off chance that it actually has metal internals.

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I think it’s a question of generation, with the plastic parts (clutch jaws and the collar at the base of the lead tube) replacing brass in later models.

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牢大怎么找到这了

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(post deleted by author)

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They should be fully interchangeable. Not just the internals, but also the tip can be swapped between alpha matic and Tk matic.

However, you need to be careful, as Tk matic with the plastic body can have either full metal internals for the early versions, or plastic for the late ones.

There are also intermediary versions. Mine has plastic in the tip and cilindrical clutch (like on your L in the first picture), but the piece on the front of the lead tube is brass. Also I can’t remove the lead tube from mine.

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It depends on the plastic components.

The lead reservoir on the Pentel P200/P320 has been plastic since 1970 (with a few minor exceptions) and they are very sturdy and in the thousands that I have collected, I have never seen any issues with them.

HOWEVER, plastic clutches are a different matter completely. In this case, metal (usually brass) clutches will usually outlast the body of the pencil, whereas plastic clutches probably won’t.

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here is a video where I take some TK Matics (including the L) apart