This specification covers six types of air hose intended for use in automotive air brake systems. The system includes all air actuated equipment leading from the air brake line. These types of hose are not to be used from the air compressor to air reservoir if air temperature is in excess of 250 F. The types of hose are as follows:

1. Type A–Hose shall be mandrel built having a tube and friction of oil resisting rubber, reinforced with cotton or synthetic cord or duck plies or a combination of both, and a cover of oil resisting compounds utilizing polymerized chloroprene as the basic material. Assemble with reusable or permanent type metal end fittings.
2. Type B–Hose shall be nonmandrel built having a tube and friction of oil resisting rubber, reinforced with cotton or synthetic cord or duck plies or a combination of both, and a cover of oil resisting compounds utilizing polymerized chloroprene as the basic material. Assemble with reusable or permanent type metal end fittings.
3. Type C–Hose shall be mandrel built having a tube of oil resisting rubber, reinforced with one braid of high tensile steel wire and a cover of oil resisting compounds utilizing polymerized chloroprene as the basic material. A cotton braid or other suitable material may be used to anchor the cover to the hose. Assemble with permanent type metal end fittings only.
4. Type D–Hose shall be mandrel built having a tube of oil resisting rubber, reinforced by two cotton or synthetic braids separated by a wire braid. All braids are to be impregnated with an oil and age resisting compound. The wire braid may be of high tensile carbon steel or of series 300 stainless steel. Hose may also have an optional thin cover of oil resisting compound utilizing polymerized chloroprene as the basic material. Assemble with reusable or permanent type metal end fittings.
   1. Class I–The wire braid shall be of high tensile carbon steel.
   2. Class II–The wire braid shall be of 300 series stainless steel.
5. Type E–Hose shall be mandrel built having a tube of oil resisting lubber, reinforced with two cotton or synthetic braids separated by a wire braid. All braids are to be impregnated with an oil and age resisting compound. This hose is not to be used on any line where abrasion of the outer cover will be encountered in its service. Assemble with reusable type metal end fittings only.
6. Type F–Hose shall be mandrel built having a tube of oil resisting rubber, reinforced with one 300 Series stainless steel braid and one fabric braid separated by an insulation layer of oil resisting rubber. The fabric braid is to be impregnated with an oil and age resistant compound. Assembled with reusable or permanent type metal end fittings.