What Is a Ball Screw and How Does It Work?

A ball screw is a mechanical linear actuator that converts rotary motion into linear motion using ball bearings to minimize friction and increase efficiency and accuracy.

What Types of Ball Screws Do You Offer?

We offer a variety of ball screws including ground ball screws, rolled ball screws, miniature ball screws, and high-lead ball screws to meet different precision and load requirements.

How Do I Choose the Right Ball Screw for My Application?

Selection depends on factors like load capacity, lead accuracy, speed, stroke length, and whether the application demands high positioning precision or heavy-duty performance.

What Is the Difference Between Ground and Rolled Ball Screws?

Ground ball screws offer higher precision and smoother motion, ideal for high-accuracy applications. Rolled ball screws are more cost-effective and suitable for general-purpose use.

What Maintenance Is Required for a Ball Screw?

Regular lubrication is essential. Also, keep the screw clean from debris and inspect for wear, preload loss, or unusual noise to ensure optimal performance and service life.

20x42x12mm Bearing: Your Go-To Deep Groove Solution for Demanding Applications

In the world of industrial procurement, few components match the versatility of a well-made 20x42x12mm bearing. We're talking about that standard deep groove ball bearing—inner diameter 20mm, outer 42mm, width 12mm—often cataloged as 6204 or its variants like 6204-2RS with seals. If you're a purchasing manager hunting for reliable stock or an engineer spec'ing out a new assembly line, this size shows up everywhere. From electric motors to conveyor systems, it's the workhorse that keeps operations spinning without drama.

At YIDI Motion, part of Hebei YIDI Import and Export Trading Co., Ltd., we've shipped thousands of these to buyers across the US, Canada, and Europe since 2020. No hype—just solid chrome steel construction, precision tolerances, and the kind of radial load capacity that handles real-world vibrations. Procurement teams come back because our 20x42x12mm bearings don't seize up after 10,000 hours like some cheaper imports. We've seen it firsthand: a Midwest pump manufacturer switched to ours and cut downtime by weeks. That's not a sales pitch; it's what happens when you source from a factory with German-imported grinders and Japanese heat-treat lines.

Let's break it down operationally. This bearing thrives under combined loads—radial up to 20kN dynamic, axial around 10kN depending on configuration. It's ABEC-3 or P6 precision standard, which means smooth rotation even at 8,000 RPM. Seals? Rubber or metal shields to keep grease in and contaminants out. We're not talking toy-grade stuff; these are GCr15 bearing steel, hardened to 58-62 HRC, with superfinished raceways that resist fatigue cracking. Importers love the open or sealed options—we stock both ZZ and 2RS versions.

Why does this matter for your next order? Supply chain snarls have everyone risk-averse. Lead times from Asia can stretch, but we container-load efficiently—FCL from Tianjin port to LA in 25-30 days typically. No minimums that scare off mid-size buyers; start with pallets of 100 and scale to OEM runs. Our team in Shijiazhuang handles customs paperwork seamlessly, HS code 8482.10.2012 for easy US entry. We've dealt with everything from Section 301 tariffs to FDA-adjacent specs for food-grade adjacent apps.

Picture your scenario: ops manager calls because the line's halted. Spindle failure on a CNC router, or conveyor idlers wearing prematurely. Root cause? Inferior grease migration or brinelling from shock loads. Our 20x42x12mm bearing sidesteps that with polyurea grease standard—stable up to 150°C, low torque drag. Maintenance crews report easier swaps; press-fit or slip-fit bores mate perfectly with shafts.

We've optimized for cross-border realities. US distributors ask for RoHS compliance—we deliver. Automotive folks want PPAP-level traceability; our ERP system spits out batch certs. And for those high-volume plays, ODM tweaks like ceramic hybrids or extended inner rings are on the table. No cookie-cutter responses; our senior techs—30% of our 100-person crew—review your CAD files directly.

This isn't entry-level advice. Over four years exporting to 50+ countries, we've learned what bites buyers. Misaligned specs lead to returns. Overlooking preload in paired setups causes whip. We guide on that upfront. Drop dimensions? Bore tolerance h6, OD H7. Radial runout under 8 microns. It's the details that prevent callbacks.

Markets shift, but demand for 20x42x12mm bearings holds steady. Renewable energy boom means more wind turbine actuators; automation surge hits AGVs. We ramped production last year, adding lines for linear motion tie-ins like ball screws. Your inquiry hits adam@yidimotion.com, and you're talking to someone who's walked factory floors, not a chatbot.

Ready to spec it? We've got inventory checks live. Or need a sample pallet for testing? Let's talk logistics fit—20-foot container holds 15,000 units net.

Market Trends Driving Demand
In-Depth Technical Specifications
Key Applications and Use Cases
Procurement Buyer's Guide
Installation and Maintenance Insights
Our Factory Capabilities
Shipping and Logistics to USA
OEM/ODM Customization
Certifications and Compliance
What Buyers Say
Frequently Asked Questions
Get Factory Pricing Now

Market Trends Pushing 20x42x12mm Bearings into High Gear

Automation's exploding. US factories ramping AGVs and robotics need bearings that take axial play without chatter. This size fits perfectly—compact footprint, high stiffness.

Renewables too. Solar trackers and small wind gens use them in slew drives. We've seen orders spike from Texas installers chasing IRA incentives. No crystal ball stuff; our export logs show 40% YoY growth to North America.

Supply risks linger post-pandemic. Spot shortages hit generic suppliers hard. Smart buyers lock in vetted sources like us—stable output, no wild pricing swings.

Operational note: Pair with linear guides for XY tables. Reduces whip, extends life 20-30% in tests we've run.

Technical Specifications: Every Dimension Covered

Parameter	Value (6204 Standard)	Notes
Inner Diameter (d)	20mm	h6 tolerance standard
Outer Diameter (D)	42mm	H7 tolerance
Width (B)	12mm	Snap ring groove optional
Dynamic Load (Cr)	20.4 kN	ISO 281 calculated
Static Load (Cor)	12.2 kN	Basic rating
Limiting Speed	14,000 RPM (open) 9,500 RPM (sealed)	Grease lubed
Weight	0.071 kg	Per unit
Material	GCr15 Chrome Steel	52100 equiv.

20x42x12 bearing 20x47x14 bearing 25x52x15 bearing

Custom variants? Extended rings, ceramic balls for high-temp or low-lube runs. Radial runout max 7μm P6. We test every batch on Mitutoyo rounds.

Where 20x42x12mm Bearings Excel in Real Operations

Electric Motors: Stator housings, fan ends. Handles misalignment common in NEMA frames.
Pumps & Compressors: Impeller shafts. Seal options block washout.
Conveyors: Idlers and tensioners. Vibration damping cuts wear on belts.
Automotive: Alternators, power steering. OEMs spec sealed for splash zones.
Industrial Gearboxes: Input stages. Pairs well with helical gears.
AGVs & Robotics: Wheel hubs, actuators. Precision for servo feedback.

Warning: Avoid in constant high-axial apps—duplex for that. We've retrofitted lines where singles failed early.

Buyer's Guide: Avoiding Common Procurement Pitfalls

Distributors overlook grease type. Lithium drops at 120°C; ours holds hotter. Check seal drag—2RS adds torque but saves relube time.

Compare radially: SKF 6204 vs ours? Identical dims, 5-10% cheaper FOB. Test preload: 50-100N typical.

Tip for US Importers: Factor LCL costs—$150/cbm from Tianjin. Bulk saves 30% landed.

Red flags: Suppliers dodging vibration tests (ISO 15243). Demand spectral plots. We provide.

ROI angle: Lifecycle beats spot buys. 18-24 months MTBF in pumps, per field reports.

Installation and Maintenance: Field-Tested Advice

Heat the housing to 80°C max. Use induction heater, not torch—avoids micro-cracks. Arbor press for shaft fit; measure interference 0.015-0.030mm.

Lube right: NLGI 2 polyurea, 30% fill. Run-in at 50% speed 4 hours. Monitor temp rise under 40°C steady-state.

Maintenance: Ultrasonic check yearly. Replace if dB exceeds 10 over baseline. Common fail: Edge flaking from poor alignment—laser check shafts.

Pro tip: In dusty shops, go ZZ metal shields. Easier clean than rubber.

YIDI Motion Factory: Built for Reliability

100 employees, Shijiazhuang base. Imported Okuma grinders, NSK superfinishers. Yield >99.2%. Traceability from steel melt to pack.

32240 Bearing

Linear motion integration: Bearings pair with our ball screws seamlessly. One-stop for actuators.

Export track: 50 countries, US top-3. No disruptions—dual sourcing steel.

Logistics: Seamless to USA Doors

Tianjin departure, COSCO/MSK lines. 25 days LAX, 35 NY. FCL 20' = 12-15k units. Anti-rust paper, plywood pallets.

Duties: 2.5% MFN. We prep commercial invoices, packing lists. DDP quotes available.

Lead: 7-10 days stock, 25-35 custom. Track via Flexport integration.

OEM/ODM: Tailored to Your Specs

Branded packaging? Done. Custom logos, colors. Hybrids with Si3N4 balls for 250°C runs. MOQ 500, prototypes free on volume commit.

Workflow: Send STEP file, 48hr quote. PPAP Level 2 standard.

Certifications: Proof in the Paperwork

ISO 9001:2015 – Quality managed
ISO 14001 – Eco compliant
RoHS – No hazmat
REACH – EU ready
SGS tested batches

Full packets per shipment. US FDA for indirect contact? Variant available.

Buyer Reviews: Straight Talk

Mike R., Procurement Mgr, Ohio Pump Co.
"Swapped to YIDI 20x42x12mm 2RS after SKF delays. Zero DOA, quieter run. Landed cheaper too. Sample batch sold us."

Sarah L., Ops Dir, Texas Automation:
"OEM run of 5k sealed units. Fast proto, perfect fit in AGV hubs. Logistics smooth—no port holds."

John K., Engineer, Cali Conveyor Firm:
"Tested open vs sealed. Yours edge out locals on speed. Greasy but stable. Will reorder racks."

Carlos M., Distributor, Florida:
"Pallet trial to FL. Customs easy, pricing beats Alibaba. Stocking 6204 now."