北京怎么查个税记录:英语翻译

刚刚由于本人操作错误,需要翻译的没有打上..对那些关心我提问的朋友表示歉意
10. THREADS
Thread forms in plastic parts may be molded, tapped, or part of an insert. This section deals with molded and tapped holes. Thread forms which are integral in an insert are dealt with under “Inserts.”
Thread forms commonly found in plastic parts include American Standard (American National), Square, Acme, Buttress, Bottle, and Unified thread forms. (Details can be found in Machinery’s Handbook, Reference 34.) Coarse Series threads are preferred and the Fine Series should be avoided, particularly under 32 pitch.
Thread froms of 5/16 in. diameter or above are often molded. Articles with external or internal thread forms can be removde from the mold either by uscrewing the molded article from the mold member, or vice versa. Mold construction is usually costly, since in many instances the mold must be built with an expensive unscrewing device ot with threaded arbors. (The threaded arbor is ejected with the molded part and is manually unscrewed.) External threads may be produced without special decices if the center line of the screw shape is located on the mold parting line of the provided it is possible to finish the threads with a thread die as a secondary finishing operation.
Preferred arrangements for the starting and stopping of threads, to avoid “feather edges.”
Threaded holes needed for assembly purposrs can be formed by tapping, particularly for smaller holes of diameter less than 5/16 in. Holes to be tapped should be slightly larger than those used in metal, and should be countersunk to avoid chipping. If the screw is not to be remove and replaced frequently, self-tapping screws should be used. A minimum edgs distance of approximately 3 screw diameters from tapped holes is recommended for adequate strength.