6308 Bearing Dimensions: Exact Specs, Applications, and Sourcing from Reliable Factories
When you're hunting down precise 6308 bearing dimensions, it's usually because a machine's downtime is costing real money, or you're speccing out a new project and need to match tolerances without guesswork. I've been in bearing procurement for over 15 years, sourcing from factories across Hebei and beyond, and I know how frustrating it gets when suppliers bury the basics or quote inflated lead times.
The 6308 is a workhorse deep groove ball bearing—40mm inner diameter, 90mm outer, 23mm wide. But dimensions alone don't tell the full story. You need to factor in load ratings, material grades, and how it holds up in your specific setup, whether that's a conveyor line in a Texas warehouse or a pump in a Midwest plant. Let's break it down properly, no fluff.
At YIDI Motion, we've machined thousands of these since 2020. Our Hebei facility runs German-imported grinders for bore tolerances down to microns. Exporting to the US, Canada, and Europe means we handle your customs headaches too. Stick around—I'll cover the numbers, real-world fits, and why skipping cheap imports saves you callbacks.
Procurement managers tell me they search "6308 bearing dimension" when rebuilding spindles or upgrading OEM assemblies. It's not just the ID/OD/width; it's dynamic load capacity (up to 40kN radial), speed limits (14,000 RPM grease lubed), and cage types—steel, brass, or polyamide. Mismatch any, and vibration eats your MTBF.
Here's a quick reality check: Standard 6308s use GCr15 chrome steel, hardened to 58-62 HRC. But for corrosive environments, we spec 440C stainless. Dimensions stay metric per ISO 15:2011, but imperial conversions matter for US buyers—1.575" bore, 3.543" OD. I've seen engineers waste days converting wrong.
Long story short, if you're verifying stock or quoting suppliers, this page has your blueprint. From exact caliper measurements to container loading for LCL shipments. And if you're ready to RFQ, our engineer Adam is one call away.
- Bore (d): 40 mm
- Outer Diameter (D): 90 mm
- Width (B): 23 mm
- Dynamic Load (Cr): 40.8 kN
- Static Load (Cor): 24 kN
That's your starting point. But read on for tolerances, variants, and why YIDI's version outperforms Alibaba specials. We've shipped over 50,000 units to North America alone—no returns reported.
Table of Contents
- 📐 Detailed 6308 Specifications Table
- 🔍 Technical Deep Dive on Dimensions
- ⚙️ Real-World Applications
- 🛒 Procurement Buyer's Guide
- 🏭 YIDI Factory Capabilities
- 🚚 Shipping & Logistics Insights
- ❓ Buyer FAQs
- ⭐ Customer Reviews
Detailed 6308 Bearing Specifications
No more PDF hunts. Here's the full spec table for the standard 6308 deep groove ball bearing, pulled from our ISO-compliant production data. Tolerances are P0 unless noted—upgrade to P6 for precision spindles.
| Parameter | Value (Metric) | Value (Imperial) | Notes |
|---|---|---|---|
| Inner Diameter (d) | 40 mm | 1.575 inch | Standard bore, h6 tolerance |
| Outer Diameter (D) | 90 mm | 3.543 inch | H7 tolerance typical |
| 23 mm | 0.906 inch | Single row depth | |
| Dynamic Load Rating (Cr) | 40.8 kN | 9,170 lbf | C3 clearance standard |
| Static Load Rating (Cor) | 24.0 kN | 5,400 lbf | Max radial load |
| Limiting Speed (Grease) | 14,000 RPM | 14,000 RPM | Oil up to 18,000 RPM |
| Weight | 0.62 kg | 1.37 lbs | Chrome steel |
| Material | GCr15 / 100Cr6 | AISI 52100 | Through-hardened |
These match SKF 6308 specs to the decimal. We stock C2/C3/C4 clearances and 2RS sealed variants. Need ABEC-3 precision? Add 15% to price, cuts noise in high-speed fans.
Technical Deep Dive: Understanding 6308 Dimensions Beyond the Basics
Dimensions aren't static numbers—they dictate fit, preload, and longevity. The 40x90x23 profile fits 6000-series slots perfectly, but chamfer radii (1.1mm min) prevent shaft nicks during press-fit.
Shoulder heights? Inner ring 1.95mm, outer 2.0mm. Critical for housing designs. We've had US importers send back bearings because they ignored fillet radii—always check r min 1.1mm.
Tolerances: For P0, bore varies -8/+18μm. Tighten to P5 for CNC tools. Vibration class V2 keeps it under 0.08g at 10k RPM. Test data from our Shijiazhuang lab confirms this.
Material matters too. GCr15 runs cool under 100°C, but pair with lithium grease for dusty plants. For washdowns, our AISI440C option resists pitting—dimensions identical, hardness bumps to 60 HRC.
6304 bearing dimension 6002 bearing dimension 6201 bearing size
One oversight I've seen: calculating ABMA load zones. 6308 handles combined loads per ISO 281 formulas. Plug your RPM and Fa/Fr into our engineer calculator for L10 life estimates over 50,000 hours.
Where 6308 Bearings Excel: Key Applications
Not every bearing suits every job. 6308 shines in moderate-speed, high-radial setups. Think electric motors (1-15HP), where its 90mm OD nests in standard housings.
- Agricultural pumps: Handles misalignment from belt drives.
- Conveyor idlers: 24kN static holds 2-ton loads.
- HVAC fans: Quiet at 12k RPM, sealed versions dust-proof.
- Auto alternators: OEM fit for Ford/GM rebuilds.
- Textile spindles: Precision variants reduce yarn breaks.
In woodworking saws, pair two 6308s back-to-back for thrust. Contractors report 20% less vibration vs. 6208 upsizes. Avoid in extreme axial—go 7208 angular contact.
Pro tip: For marine use, specify hybrid ceramic balls. Same dims, halves corrosion risk in saltwater pumps.
Procurement Guide: Sourcing 6308 Bearings Without Risks
US buyers face three pitfalls: fake certs, poor tolerances, slow ships. Vet suppliers by ABEC rating proofs and grease type (no mystery lithium). Aim for factories with 100+ employees—scale means consistency.
- Confirm ISO 9001 + RoHS.
- Request bore runout data (<5μm).
- MOQ under 100pcs for trials.
- Lead time 15-25 days FOB Tianjin.
- Packaging: Vacuum + carton + pallet.
Compare: Alibaba specials hit $3-5ea, but fail 10% in tests. YIDI quotes $6-8ea at volume, zero DOA. ROI kicks in at first no-fail run.
OEM/ODM? We customize cages or logos. Sent 5k units to a Ohio motor maker last quarter—exact dims, branded boxes.
YIDI Motion: Our Factory Strength for 6308 Production
Hebei YIDI Import & Export Trading Co., Ltd. (YIDI Motion) kicked off in 2020 with a 100-head team—30% senior techs. We grind races on DMG Mori from Germany, heat-treat in vacuum furnaces. Output: 50k bearings/month, 6308 our top seller.
Exports to 50+ countries: US gets DHL express for samples, sea for bulk. Certifications: ISO9001, CE, RoHS. 
No lead warnings—full REACH compliant.
One-stop linear motion: Pair 6308 with our ball screws for actuators. Cuts your supplier count.
Logistics: Getting 6308 Bearings to Your Door Fast
FOB Tianjin, 20' container holds 8,000pcs—$0.15/pc freight to LA. LCL? 200kg min, 25-day sail. Duty: 3.1% HTS 8482.10.5012. We handle docs.
Warning: Avoid HK forwards—adds 10 days. Direct Hebei cuts risks.
Frequently Asked Questions on 6308 Bearing Dimensions
What are the exact dimensions of a 6308 bearing?
40mm ID x 90mm OD x 23mm width. See table above for tolerances.
Can I get 6308 bearings in stainless steel?
Yes, same dims in 440C. Lead time +7 days, 20% upcharge.
What's the max temperature for 6308?
120°C continuous with standard grease. 150°C polyamide cage.
How to install a 6308 bearing?
Heat to 80°C, press inner first. Use arbor tool—never hammer.
Minimum order for custom 6308?
50pcs. Free CAD for your housing.
What Buyers Say About Our 6308 Bearings
Mike R., Ohio Motor Rebuilder: "Dims spot-on, no play in my 10HP spindles. Shipped LCL to Cleveland in 22 days. Will reorder 500."
Sarah L., Texas Distributor: "C3 clearance perfect for ag pumps. Better than NTN pricing, half the lead time."
John K., Ontario Ops Manager: "Held 1.8 tons static. Grease lasted 18 months in dusty mill."
Raj P., CA Engineering Lead: "OEM stamped fine. Tolerances beat spec—vibration down 15%."
Ready to Source Your 6308 Bearings?
Talk to our team. Free samples for qualified buyers. Volumes from 50 to 50k.
HEBEI YIDI IMPORT AND EXPORT TRADING CO.,LTD. | 16-1-1601 Aobeigongyuan, Chang'an District, Shijiazhuang, Hebei, China
Li Wei, Export Director
15+ years in bearing trade. Sourced for US OEMs like GE rebuilds. "Dimensions right, business thrives."
6308 Bearing Dimensions | 40x90x23mm Specs, Pricing & Supplier - YIDI Motion
Meta Description: Exact 6308 bearing dimensions (40mm bore, 90mm OD, 23mm width). Deep groove ball bearing specs, applications, OEM sourcing from ISO factory. Fast US shipping. RFQ now.
