There are nine causes of screw tap failure

  1. Poor quality of tap: main materials, cutter design, heat treatment, machining accuracy, coating quality, etc.

For example, if the dimensions at the transition point of the tap cross section are too different or there is no designed transition angle resulting under stress concentration, it is easy to break when used.

The cross section transition to the junction of the handle and blade is too close to the welding mouth, which results in the superposition of complex welding stress and the stress concentration at the cross section transition, resulting in a larger stress concentration, leading to the tap breaking in use.

For example, the heat treatment process is improper.

In the heat treatment of tap, the tap may crack if it is not preheated before quenching, overheated or over-burnt, not tempered in time and cleaned too early.

  1. Improper selection of tap:

High quality screw tap should be used for tapping parts with too high hardness, such as cobalt high speed steel tap, hard alloy tap, coating tap etc. In addition, different tap designs are used in different work situations. For example, the number of chip slots, size, Angle, and so on of the tap affected chip removal performance.

  1. No matching between tap and processed materials:

With the increase in new materials and the difficulty of processing, in order to meet the market demand, the variety of cutter materials is also increasing. This needs to select a suitable tap product before tapping.

  1. Small bore size of bottom hole:

For example, when machining M5 x 0.5 thread of black metal material, the cutting tap should be used to make the bottom hole with a 4.5mm diameter bit. If the 4.2mm diameter bit is misused to make the bottom hole, the cutting part of the tap must be increased when tapping, so that the tap will be broken. It is suggested to choosing the correct bottom hole diameter according to the type of tap and the material of tapping.

  1. Material problem of tapping parts:

The tapping material is not pure, and there are some hard points or pores, causing the tap to lose balance and break.

  1. The machine does not meet the requirements for the accuracy of tap:

Machine tool and clamping body are also very important, especially for high-quality taps, only certain precision machine tool and clamping body can give play to the performance of taps. Common is lack of concentricity. At the beginning of tapping, the tap is incorrectly positioned, that is, the spindle axis is different from the center line of the under hole, and the torque is too large during tapping, which is the main reason for the tap breaking.

  1. Cutting fluid and lubricating oil has poor quality:

The cutting fluid and lubricating oil have problems in quality. The quality of the processed product is prone to defects such as burrs, and the service life is also greatly reduced.

  1. Unreasonable cutting speed and feed amount:

When there are problems in machining, most users will reduce the cutting speed and feed amount, so that the propulsive force of the tap is reduced, and the thread precision of its production is greatly reduced. As a result, the roughness of the thread surface is increased, the thread aperture and thread precision are uncontrollable, and the problems like burrs are inevitable. However, if the feed speed is too fast, too much torque will cause the tap to break. The cutting speed of machine attacked is generally 6-15m/min. The tempered steel or hard steel material is 5-10m/min. Stainless steel is 2-7m/min; Cast iron is 8-10m/min. In the same material, the diameter of the tap is smaller and higher, while the diameter of the tap is larger and lower.

  1. The operator’s skills and skills do not meet the requirements:

Above these problems, need operation personnel to make judgment or feedback to technical personnel. For example, when processing blind hole threads, when the tap is about to contact the bottom of the hole, the operator did not realize that, still press the tapping speed when it did not reach the bottom of the hole, or if the chip removal is not smooth forced feed causes the tap to break. Operators are advised to being responsible.

It can be seen from above that there are various causes of tap fracture, including machine tool, fixture, workpiece, technology, chuck and cutter.

Screw Tap Grinder, Screw Tap Grinding Machine, Screw Tap Sharpener, Screw Tap Grinder Manufacturer, Screw Tap Grinder Supplier, Screw Tap Grinder for Sale, Cheap Screw Tap Grinder, Tap Cutting Tool Sharpener, Tap Drill Bit Grinder, Drill Bit Grinder

PURROS PG-Y3C Screw Tap Grinder

Universal Tools Grinder, Universal Cutting Tools Grinder, PG-600 Universal Cutter Grinder, Cheap Universal Tool Grinder, Universal Tool Grinder for Sale, Universal Tool Grinder Manufacturer, Universal Tool Grinder Supplier, Universal Tool Grinder Wholesaler, Universal Tool Grinder Exporter

PURROS PG-600 Universal Tool Grinder

When the tap wears out, we can use our PG-Y3C screw tap grinder or PG-600 universal tool grinder. But if it breaks, you can only replace it with a new one. In the use of tap, we should try to avoid the above reasons to prevent the tap fracture caused by losses.

How to solve the problem after the bit is broken?



Cause Solution
Bending, deformation, sliding Increase the rigidity of tool and machine tool, increase the rigidity of workpiece and jig
Lip Relief Angle is too small Regrinding Lip Relief Angle
High Stock Removal To reduce Stock Removal
Bit wear Use drill bit grinder to grinding
Blocking of chips Re-select the alloy bit (chip groove, helix Angle);

Re-select machining method (adjustment of feed rate, step-step method, etc.)

Poor cutting Increase the rigidity of tools and machine tools

Increase the rigidity of workpiece and jig

Predrilling center hole

The cutting plane is first adjusted or processed into a horizontal plane with a guide sleeve

Introduction about Structure of Jig Grinder

Is a development process of jig grinder is around 1940 in jig boring machine processing principle and structure of developed a precision machine tool. Machine tool was originally developed to in high hardness materials or after hardened workpiece grinding position, shape precision and surface finish of requiring high degree of the outer circle, inner hole or a taper hole.

One of the most essential variable on a jig grinding machine is the dual-spindle arrangement. The primary pin is about placed with in between 1″ or 2″ of traveling for arrangement, and afterwards the.100″ of outfeed is made use of throughout equipment procedure to outfeed right into the job. A spacer bar might be made use of in between the mill and also primary pin, permitting huge (9″ span or bigger) job to be finished. The major pin has a large range of rates to guarantee correct mill feed prices are preserved.

The development of jigs or mating openings and also secures on passes away. There are typically several outer components to a huge sharpening jig, consisting of different hydraulic electric motors, air compressors, and also numerous cooling down systems for both the hydraulic circuit and also providing coolant to the job as well as equipment itself.

The maker runs by a broadband air pin revolving a grinding bit. The air pins are detachable as well as compatible to accomplish differing surface area rates. Some pins are dealt with rate (60000 rpm), others are flexible (30000-50000 rpm), and also still others are really broadband (175000 rpm). The equipments have a conventional X-Y table with the remarkable exemption of knee traveling. All axes are indexed to.0001″ using a Vernier range on the handwheels, with greater precision readily available with making use of determining bars. The equipment head has 2 upright journeys, one harsh head modification and also the various other an accurate pin modification. The pin to which the removable air pin places likewise turns at a variable rate as well as could normally outfeed.100″ while running, once again with a precision of.0001″ on the handwheel or higher, for really accurate opening, fix as well as surface grinding. A clean jig grinder will dependably place job to a greater level of precision compared to is feasible with handwheels alone. These attributes are all crucial ready an opening and also secure system a specific range from a recommendation surface area or side.

The importance of CNC machine tool and its development history

One of the most basic concepts in advanced manufacturing technology is numerical control (NC). Before the advent of CNC machines, all machine tools were operated and controlled manually. In many of the limitations associated with manual control of machine tools, there may not be a more prominent restriction than operational skills. Under manual control, product quality is directly related to operator’s skill. Digital control is the first step in the control of machine tool.Continue reading