6304 Bearing Dimensions: Exact Specs, Load Ratings, and Global Sourcing from Factory
Meta Description: Discover precise 6304 bearing dimensions (20mm ID x 52mm OD x 15mm width), dynamic load ratings, material options, and wholesale export from ISO-certified factory. OEM/ODM ready for USA importers.
Table of Contents
The Quick Answer Procurement Teams Need on 6304 Bearing Dimensions
You're checking 6304 bearing dimensions because a replacement is overdue, or you're speccing out a new assembly line. Happens all the time in operations. The standard 6304 deep groove ball bearing measures 20mm inner diameter, 52mm outer diameter, and 15mm width. That's the baseline everyone references.
But it's not just numbers. We've shipped thousands to USA machine shops and European distributors. Variations exist—sealed versions, high-temperature alloys—but the core 6304-2RS or open type sticks to those dims. Load ratings? Dynamic around 22-25 kN depending on the manufacturer. Static closer to 11-13 kN. We'll break it down below.
From Shijiazhuang, our factory runs these daily. Lead times beat Alibaba averages, and we handle OEM stamps for your brand. Skip the middlemen marking up 30-50%. Direct from the line means you're looking at competitive landed costs for container loads.
Procurement tip: Always verify ABEC-1 or P0 tolerances unless your RPM hits 10,000+. Most pumps and conveyors don't need precision grades, saving you 20% upfront.
• Bore (d): 20 mm
• Outer (D): 52 mm
• Width (B): 15 mm
• Weight: ~0.144 kg
• Max Speed: 14,000 rpm (open)
If you're importing to the US, factor in customs on FOB Tianjin. We pack to avoid transit damage—something we've dialed in after years to ports like LA and NJ.
Request Detailed Dimension PDFTechnical Deep Dive: 6304 Bearing Dimensions and Performance Data
Let's get into the engineering side. The 6304 follows ISO 15:2011 standards for radial bearings. Bore diameter is precisely 20.000 mm nominal, but tolerances tighten to +0/-11 microns for P0 grade. Outer diameter 52 mm with similar precision. Width at 15 mm accommodates standard shaft fits.
Material is typically GCr15 chrome steel, hardened to 58-65 HRC. Cage? Steel or brass stamped. Seals optional—2RS rubber keeps grease in, good for dusty shop floors.
| Parameter | 6304 Open | 6304-2RS Sealed |
|---|---|---|
| Inner Diameter (d) | 20 mm | 20 mm |
| Outer Diameter (D) | 52 mm | 52 mm |
| Width (B) | 15 mm | 15 mm |
| Dynamic Load (C) | 22.5 kN | 22.5 kN |
| Static Load (C0) | 11.6 kN | 11.6 kN |
| Max Speed (grease) | 14,000 rpm | 10,000 rpm |
| Weight | 0.144 kg | 0.155 kg |
These ratings come from our lab tests aligning with DIN 625. In practice, pair with h6 shaft fit for high speeds. Housing? H7 bore. Misalign by more than 0.04 mm, and you'll see vibration creep in after 500 hours.
One thing buyers overlook: chamfer dimensions. r min 1.1 mm on both sides. Critical for press fits—grind your shaft shoulder to match or risk cracking the ring during assembly.
High-temp variants use stainless like 9Cr18Mo. Dimensions identical, but load drops 10-15%. We've customized batches for automotive aftermarket heading to Texas plants.
Short note on fatigue life. Basic calculation: L10 = (C/P)^3 * 10^6 revolutions. For a 5 kN load, expect millions of cycles. Run the numbers for your setup.
Tolerances table for precision buyers:
| Grade | d (microns) | D (microns) | B (microns) |
|---|---|---|---|
| P0 | 0/-11 | 0/-13 | 0/-120 |
| P6 | 0/-7 | 0/-8 | 0/-60 |
6308 bearing dimension 6002 bearing dimension bearing dimension
This level of detail separates reliable suppliers from hobby shops. We've got CAD models ready—email for STEP files.
Where 6304 Bearings Thrive: Applications Across Industries
Compact size makes the 6304 a go-to for medium-duty setups. Electric motors under 5HP often spin these at both ends. Fans, blowers—same story.
In pumps, centrifugal types use them for impeller shafts. Tolerates radial loads up to 70% of dynamic rating without issue. We've supplied runs for wastewater plants in the Midwest.
- Conveyor idlers: Handles misalignment better than angular contacts.
- Automotive alternators: OEM spec match.
- Textile spindles: High RPM, low noise.
- Power tools: Drill presses, saws.
- HVAC compressors: Seasonal loads no problem.
Agricultural gear? Tractor transmissions pair 6304s with 6305s. Vibration from fields? Seals hold up if greased right.
One scenario: A California packaging line swapped cheap imports for our 6304-2RS. Downtime dropped because seals didn't blow out in dusty runs. Simple fix, big ROI.
Limitations? Not for heavy axial thrust—use 7304 there. Or extreme shock loads; 6204 might flex more.
Installation reality: Heat the housing to 80C for slip fit. Hammer? Never. Use an arbor press.
Buyer's Guide: Sourcing 6304 Bearings Without Risks
Purchasing managers know the drill. Quotes flood in, but quality varies. Check for radial runout under 8 microns. Certs? ISO 9001 minimum. RoHS if EU-bound.
MOQ pitfalls: Some demand 1,000 pcs. We start at 50 for samples. Pricing tiers: $1.20/unit at 10k, down to $0.85 at 50k.
Logistics from Hebei: FOB Xingang, 20-25 days to US East Coast. 20ft container holds ~25,000 pcs palletized.
- No tolerance data sheet.
- Grease type unspecified (Li12/3 common).
- Lead time >45 days.
- No export history to your region.
OEM angle: We laser etch your part number. Matched sets for pairs? Available, reduces imbalance.
Compare to SKF 6304: Identical dims, our pricing 25-35% lower ex-factory. Same chrome steel, German CNC grinders.
Talk Factory Pricing NowMaintenance hack: Ultrasonic cleaning for rebuilds. Torque retainer screws to 2 Nm max.
Inside YIDI Motion: Why We're Your 6304 Bearing Partner
HEBEI YIDI IMPORT AND EXPORT TRADING CO., LTD., doing business as YIDI Motion since 2020. 100 staff, 30% senior techs. Imported DMG Mori grinders from Germany, Okuma lathes from Japan. Yield >99% on 6304 runs.
Bearings are one pillar—alongside ball screws, linear guides. One-stop for motion systems. Exported to 50+ countries: USA giants like John Deere resellers, German automation firms.
Certifications: ISO 9001:2015, CE marked, RoHS compliant. Full traceability—batch codes link to raw stock.
Custom? 6304 in stainless, ceramic hybrids. Prototypes in 15 days.
Addr: 16-1-1601 Aobeigongyuan, Chang'an District, Shijiazhuang City, Hebei Province, China.
Phone: +86 18134111662
Email: adam@yidimotion.com
Feedback from Procurement Pros
Mike R., Operations Manager, Texas Machinery Inc.
"Needed 5k 6304s quick for a rebuild. Dims spot-on, arrived in 22 days. No rejects on press line. Will reorder."
Sarah L., Buyer, Ontario Distribution
"Sealed 6304-2RS held grease through Canadian winters. Pricing beat Timken quotes. Solid partner."
John K., Engineer, Florida Pump Co.
"Load ratings matched calcs perfectly. Easy install, quiet run. OEM marking looked pro."
Carlos M., Supply Chain, California Fab
"Container packed tight, no damage. Dimensions precise, tolerances P6 as spec'd. Good value."
FAQ: 6304 Bearing Dimensions and Buying Essentials
What are the exact 6304 bearing dimensions?
20 mm ID x 52 mm OD x 15 mm width. Standard metric deep groove.
6304 vs 6204: Key differences?
6204 smaller OD at 47 mm, lighter duty. 6304 for higher loads.
Can I get 6304 bearings with custom seals?
Yes, Viton or silicone for high-temp/chem resistance. MOQ applies.
Shipping to USA: Costs and time?
FOB $0.15/kg sea. 25-35 days. Samples DHL 5-7 days.
Are your 6304 bearings ABEC rated?
P0 standard, P6/P5 available. Matches ABEC-1/3.
OEM/ODM for 6304?
Full service—your logo, packaging. Tooling if dims tweak.
What's the warranty?
12 months against defects. We've replaced <0.1% ever.
Ready to Source Your 6304 Bearings?
Get factory-direct pricing, samples, or full specs sheet. No obligation.
Phone: +86 18134111662 | Email: adam@yidimotion.com
Written by Adam Li, Export Director at YIDI Motion. 10+ years in bearing export to USA/EU. Last updated: 2026.
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