Rather than derail another thread, I'll start a new one. I have a stem that looks exactly like a Cinelli 1A stem, except that it has no 'Cinelli' marking or logo. It looks like this (from Velobase) except it's 115 mm:



However, it lacks any other markings, including any manufacturer's markings. I believe it's original to the Tommasini's early '80's build, which is mostly Campy NR except the shifters (Simplex Retrofriction) and bars (Cinelli).

Did Cinelli make 1A stems without their logo or name on them?

It could be conceivable that a few made it off the line without getting stamped. Or possibly they were intentionally left blank per the Marques request.

Does it have the made in Italy stamp and the min. insertion stamp?

See first photo.

Tommasini's in the early 1980s were sent to the US as frames, and built up either by the shop importing them, or by the buyer.

The markings on mine are identical in location and font and specifics as those in the photo from Velobase. The expansion cone, the bolts, the slot with the stress-relieving circle, are all also identical to what I see in photos of Cinelli 1A stems. The only difference I can see is no Cinelli marking. Here's a photo that doesn't show the markings well, from before I'd done any clean up:
stem

Fits 26.4 or 26.0 bars?

-Bandera

I have a few without the identification stamp on the top surface.
On occasion ebay sellers will try to exploit this as a cool feature.
Gives you the opportunity to be period correct over a wider range of years.

time for some hear-say: I recall discussion from YEARS back about who actually made components for Cinelli, and SOMEbody reported that at least the alloy forgings (for example: stems) were farmed out to outside contractors, not done under Cinelli's roof. As proof this "somebody" had a series of photos of more-or-less identical stems in which he pointed out subtle differences in the overall shape/curves as well as minor details. Whether those indicated variances in one shop's production or were a result of more than one vendor making stems was never proven, but such was his theory.
Of course I can't find this info now so have only my own faulty memory to rely on...YRMV!

This should answer your question. Bust out the callipers!

I have bar netted stems and Allen key fastened Cinelli stems missing the top stamp but have the patent stamp underneath. Eventually the patent ran out, the missing top stamp is just that, a forgotten operation.

One day I will sell some off, the stem drawer has over a dozen.

My wife thinks this is all part of a master plan to open a bike shop when I retire.

26.4.

Good to know, thanks. I have little doubt, given everything else on the bike, that this stem is period correct, and has been with this frame from the start. I can't imagine on a bike that used top of the line parts everywhere (or close to top of the line), that the OO would have scrimped in an off-brand stem.

Cinelli-ish enough for me considering the attached pics.

Despite the rigid tautology of the Period Correct Police "things" were a bit more relaxed in bits 'n bobs mfg "back when" but making sure that a critical component is safe to ride is not useless paranoia.

-Bandera

Both bolts on mine are 6 mm Allen key bolts. What is 'bar netted'?

Yes, open that bike shop! But sell coffee and donuts as well as vintage bike parts. It can be the kind of place where vintage bike folk hang out, drink coffee, and argue about Cinelli logos and obscure steel tubing and rusty head badges...

The bike came to me 'period correct', not because of anyone's fetish, but because the OO built it up the way he wanted BITD, and saw no reason to update anything, just replace consumables. It was built up with components that were top notch in 1982-83, without regard for country of origin: Simplex retrofriction shifters, Suntour freewheels and jockey wheels, Wolber dark-anodized tubular rims, Turbo saddle, Cinelli bar (and stem), and Campy NR everything else. Aside from newish bar tape/cables/tires, the last thing that I think he added was an Avocet cyclometer that dates to around 84-85.

Always a good plan for long term ownership/riding.

-Bandera

I have a stem like that as well. Identical to a Cinelli 1A, but lacking either the "Cinelli Milano" oval or the flying C logo.

Nutted, spell check is trying to edit too much. Net fail.