What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Generally, the bolts or nuts used to press workpieces or fixtures in the T-slot of the machine tool table are made into square or rectangle. Things are very inconvenient.
Yueluo relates to a self-tapping screw according to the preamble of claim 1. A self-tapping screw is known from EP0623759B1, the ratio of the outer diameter to the smaller diameter of the self-tapping screw is about 1.25-1.5, the ratio of the outer diameter to the pitch lead is about 1.5-1.6 and the thread The flank angles of , are < 50° and ≥ 35°. EP0433484B1 proposes a self-tapping screw whose thread is provided with cutting teeth of approximately arcuate design, and the cutting edge and the thread crest are at the same horizontal position and are set in opposite directions. One purpose of Yueluo is to realize a general type of self-tapping screw so that it can be screwed particularly easily into holes drilled in concrete or other materials such as bricks and the like. According to Yueluo, this object is achieved by the features in the characterizing part of claim 1, and surprisingly, it has been found that the parallel arrangement of the flanks, ie with a flank angle of about 0°, will make screwing particularly easy when screwing in , especially if the diameter of the hole varies within an allowable tolerance. One reason may be due to the fact that there is no lateral pressure on the material screwed into the thread, even if threads of different depths are cut in concrete or other materials such as brick, chipped plywood, or hardwood. The thread cuts into the material over its entire width by cutting grooves. In particular according to the embodiment of claim 11 the result is that the material cut out when screwing in the screw can be discharged without any accumulation, the dependent claims reflecting many advantages of further embodiments.
Guangdong Yueluo Hardware Industry Co., Ltd. relates to a square nut fastener for cable bridge installation, which is characterized in that it includes an upper plate body and a U-shaped jacket, and the upper plate body is provided with a downwardly protruding connecting cylinder, The two side plates of the U-shaped jacket are connected to the connecting cylinder, and the center line of the two side plates is located on the center line in the length direction of the upper plate body; the bottom of the U-shaped jacket is a wave-shaped elastic plate, which is a wave-shaped elastic plate It is fixedly connected on the two side plates, and the space enclosed by the two side plates of the U-shaped jacket, the wave-shaped elastic plate and the bottom of the connecting cylinder is the installation position of the square nut. Guangdong Yueluo Hardware Industry Co., Ltd. has a simple and reasonable structure, and is extremely convenient and flexible to operate; it does not occupy the bottom space of the C-shaped steel after installation, which increases the variety of installation, and can be applied to square nuts of different thicknesses, and the installation is firm.
Inch Screws C-1: Thread Code: The denominator is marked as 8, and then the numerator is directly called the number. Ex: 1/8 x 0.50 –PPB: 1 Thread screw x 0.50” long, PPB Ex: 5/16 x 0.50 –PPB = 2.5/8 x 0.50-PPB : 2 ½ inch screw x 0.50” long, PPB Ex: 5/32 x 0.50 –PPB =1.25/8 x 0.50-PPB: 1 ½ ½ inch screw x 0.50” long , PPB Ex: 1/4 x 0.50-PPB= 2/8 x 0.50-PPB: 2-point screw x 0.50” long, PPB Note: Coarse or fine pitch is sometimes indicated. UNF: Fine pitch: more commonly used in the electronics industry UNC: Coarse Thread: More commonly used for heavy machinery construction. Ex: 3/8 x 0.50, UNF –PPB: 3 point fine thread screw x 0.50” long, PPB. C-2: Length Code: In inches, must be multiplied by 25.40 is converted to mm. Measured with a buckle gauge, it is a metric thread when it matches the metric thread, and an inch thread when it matches the inch thread. You can also use a caliper to measure the outer diameter and pitch of the thread. The outer diameter of the metric thread is in millimeters, Such as 6, 8, 10, 12, 18, 20 mm, etc., the pitch is also in millimeters, such as 0.5, 0.75, 1, 1.5, 2, 3, etc. The outer diameter of the imperial thread is in inches, (per inch Equal to 25.4 mm) such as 3/16, 5/8, 1/4, 1/2, etc. Therefore, the reading of the outer diameter with a metric caliper often has irregular decimals. The inch pitch is expressed by how many teeth per inch. Set the caliper at 25.4 mm, align one caliper tip with the thread cusp, and the other caliper tip, if aligned with the thread cusp, is an inch thread, and if the thread cusp is not aligned, it should be a metric thread. The tip is printed on the white chalk. The chalk is clear and easy to measure. To measure the metric pitch, you should measure a length, such as 10, 15, 20, millimeters, etc., count how many teeth are included, and calculate the pitch in inches. The specified thread specification is inch thread, such as: G1. Metric threads are specified in metric units of millimeters. Such as: M30. The imperial system is determined by how many teeth there are in one inch (2.54 cm), generally a 55-degree angle. The metric system is the pitch determined by the distance between the two tooth tips, usually a 60-degree angle anchor screw: tighten the machine, etc. Screws for use on the ground. Also called anchor bolts. The difference between British and American screws is difficult to distinguish visually. The difference between British and American screws is that the rolling angle of British screws is 55 degrees, while the rolling angle of American screws is 60 degrees. These two standard screws are used in most screws. It can be used in general, but 1/2 size screws are not allowed, because the standard thread of inch 1/2 is 1/2-12 teeth, while the American system is 1/2-13 teeth.
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