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QJL Bearing Technical Data & Support


Access detailed specifications on materials, tolerances, clearances, vibration limits, and dimension charts to support your precision bearing applications worldwide. 

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High Carbon Chromium Bearing Steel

QJL uses homemade or imported vacuum-degassed, high carbon, chromium bearing steel as its standard material for precision bearing rings and balls. The table below shows the chemical composition:

Spec.No Symbol C Si Mn P S Cr Ni Mo
CHINA YJZ - 84 GCr15 0.95 - 1.05 0.15 - 0.35 0.20 - 0.40 < 0.027 < 0.02 1.30 - 1.65 < 0.025 -
KOREA STB 2 STB2 0.95 - 1.10 0.15 - 0.35 < 0.50 < 0.025 < 0.025 1.30 - 1.60 < 0.25 < 0.08
KOREA STB 3 STB3 0.95 - 1.10 0.40 - 0.70 0.9 - 1.15 < 0.025 < 0.025 0.90 - 1.20 < 0.25 < 0.08
Korea K.S D 3525 STB4 0.95 - 1.10 0.15 - 0.35 < 0.50 < 0.025 < 0.025 1.30 - 1.60 < 0.25 0.1 - 0.25
Japan JIS SW 1 SW1 0.95 - 1.10 0.15 - 0.35 < 0.50 < 0.025 < 0.025 0.90 - 1.20 < 0.25 < 0.08
Japan JIS SW 2 SW2 0.95 - 1.10 0.15 - 0.35 < 0.50 < 0.025 < 0.025 1.30 - 1.60 < 0.25 < 0.08
Japan JIS G 4805 SW 3 SW3 0.95 - 1.10 0.40 - 0.70 0.90 - 1.15 < 0.025 < 0.025 0.90 - 1.20 < 0.25 < 0.08
Japan JIS SW 4 SW4 0.95 - 1.10 0.15 - 0.35 < 0.50 < 0.025 < 0.025 1.30 - 1.60 < 0.25 0.10 - 0.25
Japan JIS SW 5 SW5 0.95 - 1.10 0.40 - 0.70 0.90 - 1.15 < 0.025 < 0.025 0.90 - 1.20 < 0.25 0.10 - 0.25
U.S.A AISI E 51100 E51100 0.98 - 1.10 0.20 - 0.35 0.25 - 0.45 < 0.025 < 0.025 0.90 - 1.15 < 0.25 < 0.08
U.S.A SAE J405 105 C 1 105C1 0.98 - 1.10 0.20 - 0.35 0.25 - 0.45 < 0.030 < 0.025 1.30 - 1.60 < 0.25 < 0.08
Germany VDEH 105 C 2 105C2 1.00 - 1.10 0.15 - 0.35 0.25 - 0.40 < 0.025 < 0.025 0.40 - 0.60 - -
Germany VDEH 105 Cr 4 105Cr4 1.00 - 1.10 0.15 - 0.35 0.25 - 0.40 < 0.030 < 0.025 0.90 - 1.15 - -
Germany VDEH 100 Cr 6 100Cr6 0.90 - 1.05 0.15 - 0.35 0.25 - 0.40 < 0.025 < 0.020 1.40 - 1.65 - -
Germany VDEH 100 CrMn 6 100CrMn6 0.90 - 1.05 0.50 - 0.70 1.00 - 1.20 < 0.025 < 0.020 1.40 - 1.65 - -

Retainers: QJL standard bearing retainers are made from quality cold-rolled carbon steel. Nylon or brass cages are also available upon request.

Seals & Shields: QJL bearing seals use quality carbon steel frameworks with Buna-Nitrile rubber as standard.

Common Bearing Grease Options

QJL Bearings recommends the following high-quality greases for consistent lubrication and bearing performance under diverse conditions:

Grease Code Grease Name Temp. Range (°C) Base Oil Thickener Water Resistant
L19 Chevron SRI#2 -20 ~ +350 Petroleum Polyurea Yes
L61 China Misc. -10 ~ +250 Diester Lithium Yes
L15 Alvania #2 -10 ~ +240 Diester Microget Yes
L05 Andoc C -20 ~ +180 Petroleum Sodium No
L60 Mobil#28 -55 ~ +180 Hydrocarbon Non soap Yes
L76 Krytox#240AC -35 ~ +290 Fluorotelomer Fluorinated oil Yes


Bearing Tolerance Grades (Comparison)

QJL precision bearings are manufactured to strict tolerance classes in line with international standards. Below is a quick comparison:

Country/Region Standard Tolerance Grades
China GB307 0 (G), 6 (E), 5 (D), 4 (C), 2 (B)
ISO ISO492 0, 6, 5, 4, 2
USA ANSI/ABEC ABEC1, ABEC3, ABEC5, ABEC7, ABEC9
Germany DIN620 P0, P6, P5, P4, P2
Japan JIS B1514 0, 6, 5, 4, 2


Radial Bearing Clearance (Single Row Deep Groove Ball Bearings)

QJL offers clearance grades C2, C0, C3, and C4 in accordance with ISO and GB standards. Typical clearance values by bore diameter are listed below:

Bore Diameter d (mm) C2 (μm) C0 (μm) C3 (μm) C4 (μm)
6–10 0–7 2–13 8–23 14–29
10–18 0–9 3–18 11–25 18–33
18–24 0–10 5–20 13–28 20–36
24–30 1–11 5–20 13–23 23–41
30–40 1–11 6–20 15–28 30–51


Radial Bearing Clearance (Single Row Deep Groove Ball Bearings)

QJL offers clearance grades C2, C0, C3, and C4 in accordance with ISO and GB standards. Typical clearance values by bore diameter are listed below:

Bore Diameter d (mm) C2 (μm) C0 (μm) C3 (μm) C4 (μm)
6–10 0–7 2–13 8–23 14–29
10–18 0–9 3–18 11–25 18–33
18–24 0–10 5–20 13–28 20–36
24–30 1–11 5–20 13–23 23–41
30–40 1–11 6–20 15–28 30–51