Summary: No one found a commercial source for fractional or whole ounce balance scale weights, so I assume there isn't one. Suggestions ranged from "string together washers" to "use fishing weights" to "coil up lengths of solder" to "make your own." Based on this last suggestion, heavy mathematics to follow ..
532 lbm/ft3 Yellow Brass (70 Cu, 30 Zn)
544 lbm/ft3 Red Brass (85 Cu, 9 Sn, 6 Zn)
12 in/ft
16 oz/lbm
4.9259 oz/in3 Density, Yellow Brass, used in calculations (below)
28.35 grams/ounce
0.24 grams is the empirical average weight of a typical hop pellet.
( 50 pellets weighs about 12 grams. )
Length Formula: l = w / p A = 4 w / p Pi d2
l = length (inches), w = weight (oz), p = rho = density (oz/in3),
A = cross sectional area (inches squared) = Pi r2 = 1/4 Pi d2
Pi = 3.14 etc., d2 = diameter of brass rod (inches squared.)
( Note: combining Pi & Rho does not yield flames!
Aw said thatsa joke, son. )
Length Inches at: Diameter Brass Rod (inches)
Desired 1/4" 3/16" 1/8"
Ounces (Decimal) 0.25" 0.1875" 0.125"
1/8 0.125 0.517" 0.919" 2.068"
1/4 0.250 1.034" 1.838" 4.136"
3/8 0.375 1.551" 2.757" 6.203"
1/2 0.500 2.068" 3.676" 8.271"
5/8 0.625 2.585" 4.595" 10.339"
3/4 0.750 3.102" 5.514" 12.407"
7/8 0.875 3.619" 6.433" 14.475"
1 1.000 4.136" 7.352" 16.543"
( Anything longer than 5" seems unreasonable to put on
a balance scale. )
How precise do I have to cut it? My hack saw blade removes up to 1/8":
Diameter Brass Rod (in.)
Weight per 1/8" using: 1/4" 3/16" 1/8"
Decimal Ounces: 0.030 0.017 0.008
Gram Equivalency: 0.857 0.482 0.214
Hop Pellet Equiv.: 3.6 2 0.9
But, in case fractional inches aren't your thing, here's a suggested simple
3-weight homebrewer's set using 1/4" brass rod, and a reasonable
perspective of what you'd miss if you rounded to the nearest inch:
1/4 oz using exactly 1 inch, is light by 3.3% = 0.24 gram = equivalent to 1 hop pellet. Pretty close. 1/2 oz using exactly 2 inches, is light by 3.3% = 0.48 gram = equivalent to 2 hop pellets. Fair, but OK. 1 oz using exactly 4 inches, is light by 3.3% = 0.96 gram = equivalent to 4 hop pellets. Not so good. A more precise 1/4" brass rod set would be: 1/4 oz is 1 and 1/32 inches 1/2 oz is 2 and 1/16 inches 1 oz is 4 and 1/8 inchesConclusions: 1. Cut as close as you want, realizing the weight-to-length relationship. Cut them long; fine tune them with a file. Cross reference them with your gram set. If you're lazy and round to the nearest inch of 1/4" brass, add a few more hop pellets, or hop cones, or boil longer, or add the hops sooner. 2. The smaller diameter brass rod gives more precision per unit length than the larger diameter rod, but the smaller diameter rod may become too long to use. I suppose you could coil up the thin brass rod if you want. 3. You don't have to use brass. Fishin' weights (in ounces) are pretty darned cheap, and you can fine tune them with a pocket knife. Of course, they look like fishing weights on a fancy balance scale.
By the way, 1 ounce = 28.35 grams = 11 US pennies = 5 US quarters.
Hope this helps. I still wish someone had a handsome brass ounce weight set for sale. (Any manufacturers out there?) Usual "NAWA" disclaimer. (Not Affiliated/Associated With Anyone/Anything referenced, indicated, or suggested in this posting.)