Lead Screw Basic Knowledge

Q:What is Trapezoidal Screw?
A:Trapezoidal screw is a kind of Lead Screw. It is a trapezoidal screw thread. Generall, a 30-degree trapezoidal screw means that the angle of the thread section extension is 30 degrees. Trapezoidal screws are divided into left-handed, right-handed and bi-directional-handed screws. The most commonly used in reality is the right-handed trapezoidal screw. It is used in conjunction with the trapezoidal nut and has better self-locking properties.

Q: What is the main difference between trapezoidal screw and Ball Screw?
A:The biggest difference is positioning and transmission. Ball screws use recirculating ball bearings to minimize friction and improve efficiency, while trapezoidal screws use the low coefficient of friction between sliding surfaces.

Q: Are the lead screw shaft and nut purchased separately?

A:Yes, unlike the ball screw, the screw shaft and nut of the trapezoidal screw are purchased separately. But it is recommended to buy in sets.

Q: Does the trapezoidal screw have an axial clearance index? What are its specifications and accuracy?

A:The trapezoidal screw has no axial clearance tolerance, only the runout tolerance in the radial direction. Trapezoidal screw specification accuracy includes thread accuracy, nut accuracy, single pitch error, cumulative pitch error, runout tolerance, length tolerance, etc.

Q:What are the classifications of trapezoidal screws? What are the trapezoidal screw nuts?

A:Trapezoidal screw classification: 1. According to the material, there are S45C trapezoidal screw and SUS303 stainless steel trapezoidal screw. The surface of the S45C trapezoidal screw is blackened. 2. According to the pitch, there are 3MM, 4MM, 6MM, 8MM and other trapezoidal screw rods. 3. According to the steps at the end, there are straight rod type, one step type, two step type, etc. 4. According to the processing technology, it is divided into extrusion molding and turning processing type. The turning processing type has high precision and can process left and right teeth and special screw rods. The material of the trapezoidal screw nut is brass, POM, etc. It usually has flange type nut, square type, straight type, etc. When it is used in conjunction with the trapezoidal screw rod, the pitch and thread accuracy must be consistent. When used with the nut bracket, it must ensure a good match between the outer circle accuracy of the nut and the accuracy of the inner hole of the bracket.

Q:What is the trapezoidal screw Support Unit?

A:There are two types of trapezoidal screw support components, square and round. They are used in conjunction with the trapezoidal screw of the support unit. They are functionally divided into fixed-side support unit and support-side support unit. The fixed side support unit is assembled from the main body, gland and Deep Groove Ball Bearing, and cannot be disassembled. Its accessories include lock nuts, collars, etc., which are mainly used to fix the Bearing seat. The support side support assembly is composed of a main body, a bearing and a circlip, and the circlip is used to fix the shaft. The trapezoidal screw support unit can be used together with the anti-rotation fixing part according to the needs, which plays a role of fixing the screw and also facilitates the installation of the position display.

Q:Can the trapezoidal screw be customized? What are the follow-up processing?
A:Can be customized. According to customer requirements, SCREWTECH can customize trapezoidal screw rods with different pitches, different materials, and different specifications. Trapezoidal screw follow-up processing refers to the processing of the end shaft, generally including plane processing, external thread processing, buckle groove processing, keyway processing, etc. The screw can be processed according to the special requirements of customers.