: Highly regarded for high-precision analytical weights. Users on metrology forums note their premium pricing but exceptional quality.
: Specializes in OIML-standard weights (E1 to M1 classes), ideal for international laboratory standards. Review: Which Class Do You Need? where to buy calibration weights
: Reliable mid-range and professional options available through scientific suppliers like Fisher Scientific. : Highly regarded for high-precision analytical weights
Buying calibration weights depends on your scale’s precision. High-end labs require ASTM Class 1 weights (Rice Lake/Troemner), while home jewelry or coffee scales are best served by affordable M1 or M2 stainless steel sets . Where to Buy: Top Vendors Review: Which Class Do You Need
The "Class" determines the weight's tolerance (how close it is to the exact mass). Typical Class ASTM 1 / OIML E2 High-precision balances (0.0001g) General Lab/Quality Control ASTM 4 / OIML F1 Precision balances (0.01g to 0.001g) Retail / Shipping ASTM 6 / OIML M1 Floor scales, postal scales, food prep Personal / Hobbyist Jewelry scales, coffee scales, home use Visual Selection Guide