KH Series — Mini Pressing Bush Linear Bearing

KH — 11 bore sizes · Press-fit outer sleeve · Compact body for space-constrained applications.

MOQ: 50 pcs. Minimum order value USD 1,500; mixed orders and trial quantities welcome.


Linear Bearings › Special Series

KH Series — Mini Pressing Bush Linear Bearing

11 bore sizes · Press-fit outer sleeve · Compact body for space-constrained applications

Compact Press-Fit Design6–50 mm BoreSingle or Double SealEasy Installation

🆕 Series Overview

The KH series is a compact press-fit linear ball bearing designed for space-constrained applications where the standard LM body length cannot be accommodated. The outer sleeve is pressed directly into the housing bore, eliminating the need for snap rings, end caps, or retaining features. Model numbers encode bore and outer diameter: KH-2030 indicates a 20 mm bore and 30 mm outer diameter.

KH bearings are factory-sealed and pre-greased, requiring no lubrication at assembly. The compact body and simplified installation make them the preferred choice for 3D printer carriage axes, small linear actuators, medical syringe pumps, and consumer electronics positioning systems. Available in 11 bore sizes from 6 mm to 50 mm.

KH bearing product view

⚙ Key Design Features

📺

Press-Fit Outer Sleeve

The outer sleeve is pressed directly into a cylindrical housing bore — no snap rings, end caps, or retaining features required. Reduces assembly time and housing complexity.

📈

Compact Body

Shorter body length than standard LM...UU for the same bore, enabling use in space-constrained housings where the full LM body cannot fit.

⚙

Model Number Encoding

KH-XXYY where XX = bore diameter and YY = outer diameter in mm. KH-2030 = 20 mm bore, 30 mm OD. Makes specification straightforward.

🔒

Factory Sealed

Pre-greased and sealed at manufacture. No field lubrication required at installation. Replace when grease is exhausted.

🔭

Chrome Steel Construction

GCr15 chrome steel (AISI 52100), hardened to HRC 58–64. Suitable for light to moderate industrial duty.

✅

11 Bore Sizes

Available from 6 mm to 50 mm bore, covering a wide range of standard shaft diameters in compact automation equipment.

📋 Complete Specification Table

ⓘ Dynamic load rating C based on 50 km nominal life (L10). Shaft tolerance h6/h7. Housing bore H7. All dimensions in mm, load ratings in N, weight in g.

Model Shaft Dia d (mm) OD D (mm) Length B (mm) Dynamic C (N) Static Co (N) Weight (g)
KH-0622 6 12 22 400 239 7
KH-0824 8 15 24 435 280 12
KH-1026 10 17 26 500 370 14.5
KH-1228 12 19 28 620 510 18.5
KH-1428 14 21 28 620 520 20.5
KH-1630 16 24 30 800 620 27.5
KH-2030 20 28 30 950 790 32.5
KH-2540 25 35 40 1990 1670 66
KH-3050 30 40 50 2800 2700 95
KH-4060 40 52 60 4400 4450 182
KH-5070 50 62 70 5500 6300 252
KH specification drawing 1

🔭 Materials & Construction

KH bearings are manufactured from GCr15 chrome-bearing steel (AISI 52100), through-hardened to HRC 58–64. The outer sleeve and ball tracks are precision-ground. The factory-applied NLGI-2 lithium-complex grease charge is sealed within the bearing at manufacture. When the grease charge is exhausted, the bearing should be replaced rather than relubricated — the sealed construction does not include a grease port. The retainer material is glass-fibre-reinforced nylon (PA66-GF30).

🏭 Typical Applications

📺

3D Printers & Additive Manufacturing

The most common application for KH bearings. The compact body and press-fit installation are ideal for FDM printer carriage rails where space is tight and assembly must be rapid.

⚙

Small Linear Actuators

Used in pneumatic and electric linear actuators where the available housing length restricts use of standard LM bearings. The press-fit outer sleeve simplifies actuator body design.

🔒

Medical Syringe Pumps

KH bearings provide consistent, low-friction linear travel for syringe plunger drives in infusion pumps and diagnostic dispensers where compact size and low particulate generation are critical.

📈

Consumer Electronics

Optical disc drive sled mechanisms, printer paper feed guides, and small scanning stages use KH bearings for compact, quiet linear positioning.

KH bearing in industrial application

🔧 Installation & Maintenance

🔧 Press-Fit Installation

Press the KH outer sleeve into the housing bore using a press tool contacting the sleeve end face only. Do not strike the bearing. Housing bore tolerance H7. Verify bore diameter with a plug gauge before pressing.

🔎 Shaft Requirement

Shaft ground to h6/h7 tolerance, HRC 58+ hardness, Ra 0.4 µm surface finish. Insert the shaft gently by hand — excessive force indicates bore damage or misalignment.

📈 No Field Lubrication

KH bearings are factory-sealed and pre-greased. Do not add lubricant at installation. No lubrication port is provided — attempting to inject grease will overpressure the seal.

⚙ Replacement Interval

Replace when detectable radial play develops or when noise increases, indicating grease exhaustion. Under moderate duty in clean environments, typical service is 500–1000 km before replacement.

🔎 Selection Guide

Select the KH bore size that matches the shaft nominal diameter. Verify that the outer diameter D fits the available housing bore with H7 tolerance. Check that the body length B is within the housing depth. If the required load capacity exceeds the KH rating, use the standard LM...UU series with a snap-ring or adhesive retention method.

①

Identify Application Type

Confirm the housing depth can accommodate the KH body length B for the selected bore size.

②

Select Bore & Model

Match bore to shaft nominal diameter. Read the model number as KH-[bore][OD], e.g. KH-1228 for 12 mm bore.

③

Verify Load & Life

Verify L10 = (C/P)³ × 50 km. If load ratings are insufficient, upgrade to LM...UU series with equivalent bore.

④

Contact Us

MOQ 100 units. Contact our team with engineering drawings specifying bore, housing, load case, stroke, and target life.

KH bearing assembly and housing

❓ Frequently Asked Questions

▶ What does KH stand for and how does it differ from LM bearings?

KH stands for Kompakt-Hülse (compact bush). Unlike the LM series which uses a return-channel recirculating system, the KH series uses a shorter, press-fit outer sleeve with a simpler ball track arrangement optimised for space-constrained applications where the LM body length cannot be accommodated.

▶ How is the KH bearing installed?

The KH bearing is pressed into the housing bore using a press tool bearing only on the outer sleeve end face. Never press through the inner bore. The model number encodes bore and outer dimensions: KH-2030 means 20 mm bore, 30 mm outer diameter. Verify housing bore tolerance is H7 before pressing.

▶ What is the maximum traverse speed?

KH bearings are rated for moderate traverse speeds consistent with their compact size. For high-speed applications (above 1 m/s sustained), specify the standard LM...UU series which has a longer recirculating ball circuit better suited to continuous high-speed operation.

▶ Can the KH bearing be relubricated?

KH bearings are factory-greased and sealed. There is no grease port for field re-lubrication. When the grease charge is exhausted, replace the bearing. Service life depends on load, speed, and contamination level — in clean, moderate-load applications, KH bearings typically achieve 500–1000 km before replacement.

▶ Are KH bearings suitable for vertical shaft applications?

Yes, with the caveat that the sealed construction retains grease against gravity migration. KH bearings are commonly used in vertical guide applications in 3D printers, syringe pumps, and small automation equipment where their compact footprint is advantageous.

📞 Ready to Order?

MOQ is 100 units per model. Provide engineering drawings with bore, housing bore tolerance, load case, stroke, speed, and target service life. All catalogue data is for reference only.

KH — 11 bore sizes · Press-fit outer sleeve · Compact body for space-constrained applications.

MOQ: 50 pcs. Minimum order value USD 1,500; mixed orders and trial quantities welcome.

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