Fender Magnet Diameters: When did they change?

[Corona Blue]

Greetings all-

Well, this thread is inspired by the recent thread on what year Fender went over to auto-traverse machines. In that thread someone mentioned that Fender didn't change over to .187" magnets until the CBS era. This whole question has really puzzled me for a long while. Many famous pickup makers, including Seymour, sell their "50's vintage" strat or tele pickups with .187" magnets... I have a few of these myself for both T and S guitars.

First off, I realize that for a lot of this stuff, Fender would have no need to retain spot-on records of when transitions of materials occurred. I realize that they were building to a specific "price point." That being said, I would think that over the years, certain generally accurate deductions can be made about the approximate times these changes occurred.

So, then, was it indeed the CBS transition (approximately) that we see .187" magnets in S and T pickups?

Also, what about the various alnico changes? I have read Bill Lawrence stating that all pickups from Fender's inception until around 1953 were .195" A3. Is this indeed the generally accepted understanding of the day?

For those of us who care to wind "vintage" types of pickups, these things seem pertinent to know. Not that we necessarily would ever be able to perfectly clone a '55 T or S pickup, but rather to guide us closer to a particular zone of texture and tone.

Yes... magnets, wire, potting mixtures, ad infinitum come into play, but... I'd really like a somewhat "definitive" answer on the magnet question (if there's one to be had).

Thanks and... happy holidays!

CB

[big_teee]

I got this from the vintage guitar website about fender magnets.

"Pre-1965 magnets are inconsistent in diameter, ranging from .185 to .197". But for the most part, they fit very tightly in the flatwork. Starting in 1965, the diameter seemed to get narrower by a few thousands of an inch. Hence the flatwork did not fit as tightly around the magnets. This causes many 1965 and later Fender pickups to "warp", where the flatwork will actually buckle and curve. Mid-1960's magnets have a smoother edge, and eventually the chamfering of the pickups stopped entirely by the early 1970's".

So from that I don't know if the A5 magnets have always been smaller than A3 or not.
As a rule now A2, A5 are .187, and A3 are .195.
Mojo is selling A5 in .195 now.
Also worth noting was that when fender stopped chamfering the magnets, this would probably cause a looser fit due to the sharp edges cutting the flatwork.
I'm wondering if most early 50's fenders were probably all with the larger A3 Magnets.
Terry

[Corona Blue]

So from that I don't know if the A5 magnets have always been smaller than A3 or not.

(snip...)

I'm wondering if most early 50's fenders were probably all with the larger A3 Magnets.
Terry

Agreed! This would seem to confirm Bill Lawrence's statement too.

The VG statement doesn't pin it down much does it?

"Pre-1965 magnets are inconsistent in diameter, ranging from .185 to .197".

Just wondering if anybody here has ever seen a .187" pole magnet in a 50's tele? I never have. Maybe Strats did in the 50's, I'm not sure, but I've never seen it. VG's statement leaves it really vague from '48-'65.

Interesting stuff...

[big_teee]

Here's more info that came from the Seymour Duncan website.
Lots of old fender info there. Here's some of the magnet info.

309. How can I tell if I have a newer or older type Fender pickup?
There are many things you need to look for and sometimes even experienced collectors or repairman have a hard time trying to determine the type or age of a pickup. The older Fender pickups usually use a .197” diameter magnets with much of the pits and roughness still left from the sand casting. The magnets usually have one end chamfered that helps direct the magnets through the flatwork without tearing much of the material away and it helps keep the flatwork tighter around the magnets. I very seldom see an old pickup that is bowed or flared because the flatwork became loose. Pickups made during the mid-60s have magnets that have been ground to a .187” diameter or 3/16”. The outer surface is much smoother and thus began the period when the bobbins started to bow and flair. Winding had to have precise tension or the ends of the bobbin would flair and cause a distorted coil. The mid-60s magnets had a smoother and less raw looking surface. The mid-60’s magnets had a smoother edge and eventually the grinding on the magnets ended. During the 70s the raw cut sharp edged magnets were back in production still with the .187” diameter. At times the Fender Stratocaster bobbins had staggered poles and some had flat poles flush with the plastic pickup cover. You need to carefully look at the various types of pickups and learn as much about the differences as you can. The early flat work till around March ‘64 used black vulcanized fibre for the bottoms of most Fender single coil pickups. During the transition a light gray vulcanized fibre was used and near the 70s a darker vulcanized fibre was used and with the resurgence of the older Fender models and designs being put back in production with an assertive effort to use black vulcanized fibre for the bottom of all Fender re-issues. It may be a small detail but an important one that adds to the confusion to all the various models of pickups on the market.

Here's the link to the fender info.
(301-325 - Seymour Duncan/Basslines) - Page 1
Later,
Terry

[Corona Blue]

Thanks Terry-

Still... this doesn't say much about when and/or for which models the changes came. One COULD read into this that all magnets were .197" until "the mid 60's" as stated. But is that really what they meant to convey?

I have access to an original '63 strat. I'll take a measurement sometime this week.

[Corona Blue]

UPDATE:

I measured the magnets on an original '63 L Series Strat yesterday. Neck stamp is Nov '63. All pickup poles measure right around .187" on my dial caliper, although the D and G poles of the bridge pickup seem to measure slightly larger at around .192". There may be some surface corrosion or potting that is skewing that measurement.

I will take a gauss reading on the pickups this weekend. That should be interesting.

[big_teee]

UPDATE:

I measured the magnets on an original '63 L Series Strat yesterday. Neck stamp is Nov '63. All pickup poles measure right around .187" on my dial caliper, although the D and G poles of the bridge pickup seem to measure slightly larger at around .192". There may be some surface corrosion or potting that is skewing that measurement.

I will take a gauss reading on the pickups this weekend. That should be interesting.

Very good info!
I bet the guitar sounds great.
While you were at it could you measure the DCR on the 3 Pickups?
You could measure through a amp cord with the Volume wide open would be great to know!
Any other info about the guitar would be great!
What it sounds like, if it is Rosewood or Maple finger board, color, etc.
Later,
Terry