Gray iron, ductile iron and compacted graphite iron were boronized with solid boron-yielding substances by box-boronizing method. Commercial EKabor(R)3 powder is used as the boronizing agent and the treatments are carried out at 850, 900 and 950degreesC for 2, 3, 4, 5 and 6 h. Thickness and microhardness of the boride layer, and the microstructure of the boronized specimens are reported. (C) 2002 Elsevier Science Ltd. All rights reserved.