Thread Size	Weight per 100 kg	Part Number
M6	0.05	FW-01
M8	0.15	FW-02
M10	0.25	FW-03
M12	0.5	FW-04

Material: Brass.  

Thread Size	Weight per 100 kg	Part Number
M6	0.05	FW-05
M8	0.15	FW-06
M10	0.25	FW-07
M12	0.5	FW-08

Material: Stainless Steel.