Spark plug date code on boxes

[Mark Milner]

I used to know this, but I guess age is creeping up here.

How do you decipher the date codes on the spark plug boxes, both the individual and the big box?

Thanks.

[Jack H.]

Re: Spark plug date code on boxes

Look for a 'clock' pattern. Should have the year of mfgr in large numbers in the center of the clock surrounded by individual month numbers in a circular pattern. If I recall correctly, individual month numbers were removed from the circular pattern as each month of production expired.

[Jeffrey S.]

Re: Spark plug date code on boxes

Mark:
On the small boxes there are numbers up to 12 and the last 2 digits of a year. The first number in the list to 12 is the month. They start in Jan with 1 through 12 listed and delete one each month. If the numbers run from 6 to 12 then the box was printed in June of the year listed. This only the printing of the box- not necessarily the manufacture of the spark plug. The large boxes I have are marked this way also and some are marked with just the month outside a cicular logo with the year inside the logo.
Jeff

[Mark Milner]

Re: Spark plug date code on boxes

Thanks, Jack and Jeff.

The boxes I have a single number inside the clock. They are old ACniter and Fire Ring boxes in the familiar AC blue and white box.