These are U.S. Standard and Metric (B.S.) Standard wire mesh sieves. These sieves conform to all ASTM E-11, AASHTO T-27 & M-27, NIST, ISO 3310-1, and BS410 specifications. Each sieve is supplied with a serial number and a matching certificate of compliance. The sieves are constructed of metal frames which are seamless and have extended bottoms. The sieve cloth is mounted without distortion and the joints are smooth to prevent catching of material. Sieves of the same diameter can be nested on top of each other. There is no price difference for full, intermediate, or half height sizes. Sieve certification (calibration) is available at additional cost.