discount 70% in 2018-09-22 to 2018-09-24
price: USD$ 18.90
freight :USD$7.00,(Postal parcel)
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N+SP spiral wire attack
Metric coarse tooth (M)
Screw tapping accuracy level: YAMAWAP
Material for screw tapping: HSS-E
The number of teeth cut into the mouth: 2.5 teeth
Surface treatment: N-SP (OX) - acidification
Suitable for being cut wood:
Medium and low carbon steels, copper, aluminum and magnesium alloys with tensile strength less than 750N/mm
Anti - joint strength 600-900N/mm medium high carbon steel, alloy steel, bronze, etc.
Spiral tap (SFT)
Spiral screw in blind hole tapping, cutting steel continuous discharge effect is good. The cutting speed can be increased by 30%-50% faster than that of the straight fluted tap because the cutting of the right flute groove about 35 degrees can be carried out from the hole, and the high speed tapping effect of the blind hole is good. Cast iron and other cutting into small pieces of material, poor effect.
The main parameters of the tap are the same as the machined screw holesThreading toolFor cutting or trimming internal threads. When machining small size screw holes, tap is almost the only machining tool. The tap is often divided into hand taps, machine taps, nut taps (used for thread cutting in the nut machine), die tap (used for cutting and correcting die thread), pipe thread tap and taper thread tap
Machine and hand taps are commonThreadStandard tap. In China, it is customary to call high speed steel molar taps as machine taps, and carbon tool steels or alloysChisel tool steelThe teeth (or incisor) taps are called hand taps, in fact, the structure and working principle of the same are basically the same. Usually, the tap is made up of the working part and the shank. The working part is divided into the cutting part and the calibration part. The former has a cutting cone, which is responsible for the cutting work, and the latter is used to calibrate the size and shape of the thread.
Taps are usually divided into single or group. Small and medium sized through hole can be attacked by single tap at one time. When machining blind hole or large size screw hole, the group tap is usually used, that is, the processing of one screw hole is completed by more than 2 taps. Group taps have two designs: equal diameter and unequal diameter. The taps of equal diameter design only have different length of the cutting cone; the thread sizes of the taps designed with unequal diameters are different, and only the last one has a complete tooth shape. The cutting load distribution of taps with unequal diameter design is reasonable, the machining quality is high, but the manufacturing cost is also high. Trapezoidal thread taps are usually designed with unequal diameters.
In order to improve the cutting efficiency of tap, improve the chip and chip removal, reduce tooth breaking and breaking, modern taps have a variety of new structures. (1) screw tip tap: the cutting part is inclined to grind and form a negative edge angletoolWhen the chip is removed during cutting, it is suitable for machining through holes. The spiral groove taps: the chip groove is spiral, in processing the blind hole right thread, the tap must make the right spiral chip groove, so that the chip is discharged forward, not scratch the thread. (3) no slot extrusion tap: the plastic deformation of the metal formed by extruding the hole wall is mainly used for processing aluminum alloy, copper and other plastic materials, and can also process low carbon steel and stainless steel. The taper of the front end of the tap is conical thread. In order to reduce friction and reduce extrusion force, the tap section is made into polygon. The extruding tap has high strength, and is especially suitable for machining small size screw holes with diameters less than 6 millimeters. The screw tap along the cutter tooth spiral direction and remove a tooth, thus increasing the chip thickness, in favor of chip breaking and chip, used for processing stainless steel workpiece. The inner chip removing taps: the chip is discharged from the inner hole of the tap, and is used for processing large size screw holes. The automatic contraction tap: tapping tap tooth after automatic inward contraction for quick exit. The tap is a knife tooth distribution in spiral linebroachIt is often used for machining trapezoidal and square thread. 8Cemented carbideTap: mainly used for processing cast iron and non-ferrous metals, cutting efficiency and tool life is higher.
The machine tap is made of high speed steel material, suitable for tapping the screw holes of high strength materials such as carbon steel, cast steel, alloy steel and so on. For machine taps (inch), the tooth angle is as follows55°It is made of high speed steel, which is suitable for processing inch systemBSW、BSFInternal thread. Machine taps (US) is a unified thread tap machine, the tooth type angle60°High speed steel is used to grind thread shape. It has the characteristics of high precision, good performance and long service life. Suitable for machining Unified threadsUN).1B、2B、3BThrough hole or through hole.
Machine tapThe effect depends on its original material, heat treatment, groove type, precision, tapping machine, cutting speed and workpiece material, the hardness of the workpiece, the operation staff quality, and the current hardware on the market machine tap grades many because of the use of materials or different processing, with the specifications of the product price a lot of difference, so that buyers like smoke and mirrors, I do not know what to buy as well, and once to buy inferior products, light will cause the workpiece scrapped when tapping, and will affect delivery. As an insider, it is recommended that you choose the taps, the raw material of the taps, heat treatment, groove type should pay special attention to, the following to teach you a few simple methods:
1The initial inspection: check the tap cone whether there is black, yellow or burn traces, whether the square is bright and clean, whether the mark is clear, etc..
2Look: look, went through the front end of the screw thread tap groove grinding(Chamfer)Whether the cutting edge of the cutting groove has a quick mouth, the front thread of the high quality tap is positive7Font, and inferior tap will be inverted7A word orUGlyph. This kind of tap will cause two times of cutting, break easily and affect the precision of the thread when it comes out of the wire tapping;
3Test of heat treatment: tap is parabola in the air5riceWhether or not the flat falling is broken or not, indicating that the brittleness is large;
4And knock off tap, if the fracture is a type of plagioclase, and the grain fracture in the(Metallographic structure)The fine knot indicates that the heat treatment and the material are good; if the fracture is flat or the inclined plane is very short, the grain is fine(Metallographic structure)Crude means heat treatment or bad material