MANDATORY APPENDIX II

MAGNETIC PARTICLE EXAMINATION: PROCEDURE AND

ACCEPTANCE STANDARDS

II-1 PROCEDURE

Magnetic particle examination procedure for castings

shall be in accordance with ASTM E709, Standard

Guide for Magnetic Particle Testing. For forgings,

plates, and bars, the examination procedures shall be

in accordance with ASTM A275, Magnetic Particle Exam-

ination of Steel Forgings.

II-2 ACCEPTANCE STANDARDS

II-2.1 Castings

Maximum acceptable indications are as follows:

(a) Linear Indications

(1) 8-mm (0.3-in.) long for materials up to 13-mm

(0.5-in.) thick

(2) 13-mm (0.5-in.) long for materials 13-mm to 25-

mm (0.5-in. to 1.0-in.) thick

(3) 18-mm (0.7-in.) long for materials over 25-mm

(1.0-in.) thick

For linear indications, the indications must be sepa-

rated by a distance greater than the length of an acceptable

indication. A linear indication is one with length in excess

of 3 times the width.

(b) Rounded Indications

(1) 8-mm (0.3-in.) diameter for materials up to 13-

mm (0.5-in.) thick

(2) 13-mm (0.5-in.) diameter for materials over 13-

mm (0.5-in.) thick

Four or more rounded indications in a line separated by

1.5 mm (0.06 in.) or less edge-to-edge are unacceptable.

Rounded indications are those that are not defined as

linear indications.

II-2.2 Forgings and Rolled or Wrought Material

Maximum acceptable indications are as follows:

(a) Linear Indications

(1) 5-mm (0.2-in.) long for materials up to 13-mm

(0.5-in.) thick

(2) 10-mm (0.4-in.) long for materials over 13-mm

(0.5-in.) to 25-mm (1-in.) thick

(3) 15-mm (0.6-in.) long for materials over 25-mm

(1.0-in.) thick.

For linear indications, the indications must be sepa-

rated by a distance greater than the length of an acceptable

indication. A linear indication is one with length in excess

of 3 times the width.

(b) Rounded Indications

(1) 5-mm (0.2-in.) diameter for materials up to 13-

mm (0.5-in.) thick

(2) 8-mm (0.3-in.) diameter for materials over 13-

mm (0.5-in.) thick.

Four or more rounded indications in a line separated by

1.5 mm (0.06 in.) or less edge-to-edge are unacceptable.

Rounded indications are those that are not defined as

linear indications.

An indication may be larger than the imperfection that causes it;

however, the size of the indication is the basis for acceptance evaluation.

ASME B16.34-2020

189