Parts are rack or barrel plated to ASTM B standard thicknesses from ” to “, depending on the base metal and application. Pure % tin is. Designation: B – 97 (Reapproved )e1 Standard Speci?cation for Electrodeposited Coatings of Tin1 This standard is issued under the. ASTM B Standard Specification for Electrodeposited Coatings of Tin.
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Three test methods are described in Appendix X3, while a simple dip test is given in Test Method B Coatings shall be sampled, tested and conform accordingly to specified requirements as to appearance, purity, local and mean thickness, integrity including gross defects, mechanical damage, and porosityadhesion, solderability, and hydrogen embrittlement relief. The test piece is held b54 a clamp that extends from an arm directly over the solder bath.
When Guide B is speci? Black spots or lines are evidence of mechanical damage or gross defects. Addition of the sulfuric acid may be made before the test specimens are placed in position, provided that the cabinet is closed within 5 min of addition of the acid.
ASTM B – Tin Plating by Keystone Finishing
The values given in parentheses are for information only. Corrosion can be expected at discontinuities in the coating such as pores due to galvanic couples formed between the tin and the underlying metal through the discontinuities, especially in humid atmospheres. These alloying additions, particularly the?
The procedure is known as sampling inspection. Link to Active This link will always route to the current Active version of the standard.
ASTM B – 13 Standard Specification for Electrodeposited Coatings of Tin
This b455 is a brief summary of the referenced standard. Porosity increases as the coating thickness decreases, so that minimum thicknesses must be specified for each application.
They shall be adherent and visually free of blisters, pits, peeled areas, cracks, nodules, and unplated areas. It is the responsibility of astmm user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For mill products, refer to Speci? Test Method B contains four sampling plans, three for use with tests that are non-destructive and one for use when they are destructive.
Examination of 43 magni? If b55 feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address aatm below. Therefore, in designing for low-voltage electronic equipment where components are closely spaced, tin coatings should either not be used, or whisker formation should be inhibited or prevented by the application of prevention methods. If the quality of the deposit is also poor, the blister may crack, and the plating will peel away from the basis metal.
This specification does not cover hot-dipped tin or other non-electrodeposited coatings, and mill products. Suspend the test specimens above this solution on nonmetallic supports, with the surfaces of the specimens not less asstm 25 mm 1 in.
Current edition approved April 1, Practically all of the following methods take into account the chief cause of tin whiskering, which is the presence of stresses in the tin coating 8: They shall not be stained or discolored. There needs to be sufficient free tin below the oxide aatm in order for this to occur, because the intermetallic compounds formed from tin and the basis metal will not react in this way 7.
The mechanical forces of the molten solder and tin?
Visual examination, time of wetting, measurement of area of spread, and calculation of spread values are used to assess solderability 1, 2.
This standard has been approved for use by agencies of the Department of Defense. The size should be sufficient to accommodate the test specimens with their lowest wstm at least 75 mm 3 in.
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this standard. Class V545 Minimum Thickness 2. Class A is often used for tin coatings that are not to be soldered, but must function as low-resistance electrical contact surfaces. Evidence of diffusion is the formation of a layer of copper-tin intermetallic at the interface and diffusion of zinc to the surface if the substrate is brass.