Shenzhen Zhonglichuang Bearing Co., Ltd. supplies ball screws SFU1204  SFU1605 SFU2005 for non-standard equipment, animation equipment, automation equipment, and precision miniature ball screws!

Ball screws and nuts
Screw material: Japanese standard S55C high carbon steel (CF53# high carbon steel)
Material:
Nut material: alloy structural steel (20CrMo)
2
Accuracy grade: C7 or P7
Tolerance grade: G6 or H7
3 Straightness: 500mm runout 0 to 3 threads (C4 standard
5 Hardness: HRC 58-62

1. Nominal diameter

This refers to the outer diameter of the screw. Common specifications include 12, 14, 16, 20, 25, 32, 40, 50, 63, 80, 100, 120. However, please note that among these specifications, generally only sizes 16 to 50 are kept in stock.

Nominal diameter is basically proportional to the load capacity; the larger the diameter, the greater the load. Specific values can be found in the manufacturer's product catalog. Here, we only explain two concepts: dynamic rated load and static rated load. The former refers to the rated axial load under motion, while the latter refers to the rated axial load at rest. When designing, refer to the former. It is important to note that the rated load is not the maximum load; the smaller the ratio of the actual load to the rated load, the higher the theoretical lifespan of the screw. Recommendation: Try to select diameters between 16 and 63.

2. Lead

Lead refers to the linear distance the nut travels when the screw rotates one full revolution. Common leads (unit: mm) include: 2, 4, 5, 6, 8, 10, 16, 20, 25, 32, 40. Parameters related to lead are the nut's movement speed and the linear thrust that the ball screw can provide.

The larger the lead, the faster the linear movement speed at the same rotational speed. The specific calculation relationship is:

v = r * i

v: Nut movement speed (unit: mm/s)

r: Screw rotation speed (unit: r/s)

i: Lead (unit: mm)

Relationship between lead and screw thrust:

F = (2 * π * T * n) / i

F: Screw thrust (unit: N)

T: Torque provided by the motor (unit: N·m)

n: Transmission efficiency (ball screw transmission efficiency is generally 85%-95%)

i: Lead (unit here: m)

3. Length

Length involves two concepts: total length and thread length. Some manufacturers only calculate the total length, while others require providing the thread length. Thread length also consists of two parts: total thread length and effective travel. The former refers to the total length of the threaded portion, while the latter refers to the theoretical maximum length of the nut's linear movement. Thread length = effective travel + nut length + design margin (if a protective cover needs to be installed, also consider the compressed length of the cover, generally calculated as 1/8 of the cover's maximum length).

When designing and drafting, the total length of the screw can be roughly accumulated based on the following parameters: Total screw length = effective travel + nut length + design margin + length of both end supports (bearing width + lock nut width + margin) + power input connection length (if using a coupling, it is approximately half the coupling length + margin). It is particularly important to note that if your length is excessively long (greater than 3 meters) or the length-to-diameter ratio is very large (greater than 70), you should consult the manufacturer's sales personnel in advance regarding feasibility of production. Generally, domestic manufacturers offer standard products up to 3 meters and special products up to 16 meters, while foreign manufacturers offer standard products up to 6 meters and special products up to 22 meters. This doesn't mean domestic manufacturers cannot produce longer screws, but the price for custom orders can be quite high. Recommendation: Try to select lengths under 6 meters; for longer requirements, using a rack and pinion is more cost-effective.

Standard ball screw models:

Complete list of ball screw models: SFU1605 SFU1610 SFU2005 SFU2505 SFU2510 SFU3205 SFU3210 SFU4005 SFU4010 SFU5010 SFU6310 SFU8010 DFU1605 DFU1610 DFU2005 DFU2505 DFU2510 DFU3205 DFU3210 DFU4005 DFU4010

Product images: