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[UNITEK Technology leads to efficiency] Fasteners, choose common misconceptions about, see you in a few?

2016-04-21 10:25:27 Jiaxing Unitek Machinery Co., Ltd. Read

Selection of fasteners, the first option to use from the national standard specifications, and then in the industry choice, when necessary, to design according to host special needs.And in all the requirements, locking and prevent rupture is the conditions of the two main consideration.


Fine to coarse generation
An important connection machine, fly, such as transmission shaft, shaft, etc., the bolt multi-purpose fine thread.When the missing parts in maintenance, someone replaced with coarse thread bolt.Due to large fine thread bolt diameter, pitch and exterior Angle is small, has the advantages of high strength, good self-locking performance, ability to withstand the shock, vibration and the exchange of load;With coarse thread bolt after substitute, loose or broken off, easily, cause mechanical accident.
Pore not worthy
Machine carry horizontal load and shear force of bolts (e.g., transmission shaft, the flywheel bolt), they cooperate for transition fit with the bolt hole, assembly should be solid and reliable, and can withstand the lateral force.People do not pay attention to check in the assembly, a big gap between bolt and bolt hole are still installed, the result is loose or cut off the accident.
Thickening of the nut
Some people often make the mistake of thinking that, thickening nut can increase the thread number of the work world, so as to improve the reliability of connection, actually the thicker the nut, the load distribution between different ring thread is uneven, the more easy to cause loose connection.
one nut more washer
In the installation, can appear sometimes assembly after the bolt is too long phenomenon, so someone will put many spring washer in a bolt and so, in the process of solid spring washer uneven, some will be broken, decrease the bolt pre-tightening force;Or producing eccentric load, reduce the reliability of bolt connection.
The gasket is too large
Sometimes the lack of proper washer, someone with inner diameter larger washer instead.Under the bolt head and gasket contact area is small, so the gasket of the bearing pressure or locking force, under the effect of vibration and impact load, the bolt is loose.
torque non-compliant
Many people think the bolt should be "rather tight not loose", and consciously increase bolt tightening torque, the result that bolt slide fastener, on the other hand, the importance in the needed torque tighten bolts, and others, graph save trouble with adjustable wrench to twist, the result often loose due to lack of torque, mechanical failure.
lock unsuitable
Important bolt lock locking device should be taken to check after assembly.When split pin locking is used, is a common mistake is to use carefully open the lock or half piece of open lock locking;USES the spring washer locking, common mistake is washer openings the offset is too small, loss of elasticity;Using lock locking, common mistake is to lock lock plate at the edges and nut;With double nut locking, a common mistake is to thinner nut is installed in the outside, and the screw is not tight.

 fake fasten

Bolt, nut or screw hole threads inside the rust stains, scale, iron filings, sand and other impurities, or join a joint surface impurities such as burrs, sediment, and not be removed before assembly, when tightening bolts, due to the effect of blocking of the impurity, on the surface of screw tightly, torque value meet the requirements, but actually has not really compact connection;In addition, there is a kind of circumstance, because the screw hole jacking of impurities such as sludge, scale effect, while the bolt torque conform to the rules, but the work piece and no pressure.Under such false strong, vibration, impact load and temperature variations make bolts loose soon.

Selection of fasteners, the first option to use from the national standard specifications, and then in the industry choice, when necessary, to design according to host special needs.And in all the requirements, locking and prevent rupture is the conditions of the two main consideration.

  • UNITEK technology leads to efficiency , high strength and high corrosion resistance of stainless steel fasteners            


Jiaxing UNITEK mechanical technology co., LTD. Is the first domestic manufacturing high strength and high quality architectural stainless steel fasteners production enterprise, broke the situation of such products long-term dependence on imports.Companies with high hardness, high strength martensitic stainless steel (SUS410) drlling self-drilling screw, self-tapping screw, high strength stainless steel bolts engineering classes give priority to dozen of product construction fasteners, products widely used in domestic and foreign high-end steel structure building, outdoor facilities and subway, tunnel, highway, power grids, automobile, shipbuilding and other industries;The capital airport T3 terminal, CCTV tower, Beijing south railway station, Shanghai hongqiao high iron, 2022 Asian games stadium in hangzhou, shougang Beijing Olympic sports center, Shanghai Disney tang steel, baosteel zhanjiang iron and steel, and so on domestic thousands of landmark building has a close bond technology products in their lives.Products with high strength, good corrosion resistance, safe, diverse and features such as saving.



1. High strength - responsible for the quality

Tighten tensile strength high, concluded the superior effect

2. Responsible for security - for life

Tensile, shear, torsion, anti-seismic

3. Use - responsible for the job

Speed is fast, assembly of high efficiency and wide applicability

4. Corrosion - responsible for the owner

Quality, one hundred, one hundred years of life

5. Variety - responsible for the design

Superior innovation, manufacturing capacity

6. Save - good screw to save

Is more efficient to let you save worry save trouble to save money