I can now decipher when our '70s-'90s Skil power tools were made.
1. The first letter is the plant code (example "H"). This may be preceded by a number (example "1H").
2. The second and third letters overall are the part of the code that deciphers when the product was made. The first of these two designates the calendar year, which only works for products made between 1974 and 1997, as Skil ran out of letters to use in this system and thus implemented a newer date code system they still use today. The list of years designated by this first part of the date code are:
A=1974, B=1975, C=1976, D=1977, E=1978, F=1979, G=1980, H=1981, J=1982, K=1983, L=1984, M=1985, N=1986, P=1987, Q=1988, R=1989, S=1990, T=1991, U=1992, V=1993, W=1994, X=1995, Y=1996 and Z=1997. Letters "I" and "O" are skipped to avoid confusion with numbers "1" and "0" respectively.
3. The second part of the date code, the third letter, designates the calendar month (again, the letter "O" is skipped to avoid confusion with the number "0"): N=January, P=February, Q=March, R=April, S=May, T=June, U=July, V=August, W=September, X=October, Y=November and Z=December. This part of the code may also be followed by another number.
For example, my dad's Skil #576 saw has the date code "1HKZ1" embossed on its nameplate. "KZ" means December 1983.
His former #2305 cordless screwdriver has the date code "7RMU3" embossed on its nameplate, where "MU" means July 1985.
Let's see how old your '70s-'90s Skil products are after you read what I've just typed.
More examples:
Skilsaw #1 (Handy Dan exclusive series), type 1, date code #HGW1 (GW=September 1980)
Skilsaw #574, type 7, date code #WAS1 (AS=May 1974)
Skilsaw #574, type 10, date code #HJY1 (JY=November 1982)
Skilsaw #576, type 2, date code #HGR3 (GR=April 1980)
Skilsaw #576, type 4, date code #5HLS1 (LS=May 1984)
Skilsaw #936, type 8, date code #HGS3 (GS=May 1980)
Skilsaw #1978, type 1, date code #HFS1 (FS=May 1979)
Skilsaw #5150, type 1, date code #3HRU4 (RU=July 1989)
Skilsaw #5150, type 1, date code #4HUW1 (UW=September 1992)
Skilsaw Professional #77, serial #J338101, date code #SHP3 (HP=February 1981)
Skilsaw Professional #825, type 13, serial #AA231014, date code #4WEP4 (EP=February 1978)
Skilsaw Professional #5510, type 1, serial #HB655797, date code #1HNW1 (NW=September 1986)
Skilsaw Professional #5510, type 1, serial #HD112305, date code #1HTT2 (TT=June 1991)
Skil #96 3.25" Plane, serial #A66208, date code #ZJX3 (JX=October 1982)
Skil #595 3" Belt Sander, type 4, date code #SKY (KY=November 1983)
Skil #2007 3.6V Quick-Charge Cordless 3/8" Drill and Screwdriver, date code #RJW3 (JW=September 1982)
~Ben
