Age of Bpt based on Serial #?

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Age of Bpt based on Serial #?

Post by Matt_Isserstedt »

Serial number on my knee is...the fraction (12/BR) followed by 213679.

Not sure if the milling heads are tied to manufacturing dates but that is J227366.

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Re: Age of Bpt based on Serial #?

Post by Hanz »

Matt, here is a link to a serial # chart- ... eport.html

If I understood the story right, the head and knee serial numbers became out of sequence when they started making varispeed heads, because they were still making step pulleys at the same time for a short while. HTH!

Oh, and the 12BR stands for 12" of 'Y' travel...
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Re: Age of Bpt based on Serial #?

Post by Chris_W »

Hi Matt,
I show your mill as a 1980 and the head as a 1981. Someone had posted the serial numbers on the old board and I saved it.

Thanks Guys nm

Post by Matt_Isserstedt »

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Re: Age of Bpt based on Serial #?

Post by Dick_Parker »

My sample is small, but I have not seen yet a Bridgeport that had the same S/N head as the S/N on the knee. I got some old catalogues off Ebay and after perusing them I may have stumbled on the answer as to why the head S/Ns do not match the machine S/N.

Apparently the Bridgeport Machine co. (formerly Bridgeport Pattern and Model co.) sold "attachments" early on. These attachments are what we now know as "heads" and there were 6 of them. They had a 1/4 hp attachment (head) (rigid spindle) which thay called the Model "C" attachment, a 1/2 hp attachment with rigid spindle callled the "Model "R" attachment, a 1/2 hp attachment with moving spindle called the "Master Milling, Drilling, and Boring attachment called the Model "M" attachment, a cherrying attachment which they called the Model "T" attachment, and a shaping or slotting attachment which they called the Model "E" attachment and a 1 hp milling, Drilling, and Boring head made for precision work they called the Model "J" attachment (what we know of today as the J head).

All of these "heads" were sold separately as attachments for use on other manufactures basic machines. Bridgeport sold adapeters depending on who's machine your attachment was to go on.

In 1938 Bridgeport introduced the "Turret Milling Machine" (round ram)which was offered for sale with or with out the attachment (head).

The "J" attachment general layout drawing is dated 1949 which predates the introduction of the "v" ram which was introduced with Turrent Milling Machine S/N BR31619 in 1957.

The catalogues show round ram machines pictured with model "J" attachments, which is consistent with the dates.

The catalogues show "V" ram machines with the Master Milling, Drilling, and Boring attachment ("M" head).

So bottom line, the heads were made, serialized, and sold separately from the basic machine. Near as I can tell from this information, there appears to be no tie between the head S/N and the basic machine S/N.

By the time the operators manual came out for the Turrent Milling Machine with the 2J head there appears to be no support for the "C", "R", "T" attachments in the manual, only the "M" head, "J" head and "E" head.

Anybody have anything else to add here?? I'm always curious

Dick in Ct.
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Re: Age of Bpt based on Serial #?

Post by AndrewMawson »

In the UK they were originally made under license by Adcock & Shipley with the last three / four digits of the serial number being month / year so my 1969 machine ends -6-69 meaning made June 1969.

Later Bridgeport bought Adcock & Shipley and made them themselves
Andrew Mawson
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Re: Age of Bpt based on Serial #?

Post by gamachinist »

Thanks Hanz for the link!
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Re: Age of Bpt based on Serial #?

Post by Steve_in_Mich »

Matt, base serial numbers are available on the web (if you haven't found them I can send you a copy. The serial numbers for the heads are a little harder to find - in fact I don't have anything on them - but would like to. I recently offered this info hoping it would help with dating a Bridgeport.

Bridgeport Age
Many years ago I had advertized some machines for sale, a Bridgeport mill amoung them. Two equipment resellers showed up, with others, producing documentation to date both the base and head on this mill. My point - check with any local equipment/machine dealers, they may have the same crib sheets.

BTW, they gave the same dates for each independently
Just because you don’t believe it - doesn’t mean it’s not so.
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Re: Age of Bpt based on Serial #?

Post by nitearc »

Hi Matt, if you go to: www. there will be some information on the page, and with an e-mail or a call to the 800 # you should be able to get all the information you should need. I do some welding work for this company, and I can highly recomend them both as competent craftsman and really nice people.
Good luck ............. Mike
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