Washers - Bushing, Shoulder

Part Number	Description / PDF	Quantity
12SWS0636 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	8873
10SC250075 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	22899
12SWS2507 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	15421
12SWS1240 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	22390
12SWS0876 Richco, Inc. (Essentra Components)	SHOULDER WASHER .200 ID .390 OD	1000
12SWS0233 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	9478
12SWS0629 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	18136
B-531-V2325 Aearo Technologies, LLC – a 3M company	BUSHING 0.36" THERMOPLASTIC	0
12SWS2509 Richco, Inc. (Essentra Components)	SHOULDER WASHER .201 ID .635 O	0
B-532-V2525 Aearo Technologies, LLC – a 3M company	BUSHING 0.42" THERMOPLASTIC	0
12SWS0610 Richco, Inc. (Essentra Components)	SHOULDER WASHER .256 ID .348 OD	990
12SWS1200 Richco, Inc. (Essentra Components)	SHOULDER WASHER .208 ID .615 O	0
3053 Keystone Electronics Corp.	WASHER SHOULDER #4 NYLON	9938
12SWS3504 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	4961
10SCM002006 Richco, Inc. (Essentra Components)	SHOULDER WASHER 2.1MM ID 4.2MM O	9850
FB1430A Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL,.375 IN	3991
12SWS0467 Richco, Inc. (Essentra Components)	SHOULDER WASHER .091 ID .312 OD	930
12SWS1207 Richco, Inc. (Essentra Components)	SHOULDER WASHER .219 ID .625 O	0
MNI5/16-12 Richco, Inc. (Essentra Components)	WASHER SHOULDER 5/16 NYLON	4695
16CW312050 Richco, Inc. (Essentra Components)	CUPPED WASHER, 5/16 SCREW, .320	3000

Washers - Bushing, Shoulder

1. Overview

Washers - Bushing, Shoulder are precision mechanical components combining the functions of a bushing and a washer. Featuring a stepped outer diameter design, they provide axial load distribution while maintaining precise radial alignment. These components are critical in modern machinery for reducing friction, preventing vibration-induced loosening, and protecting assembly surfaces. Their engineered geometry enables simultaneous load-bearing and spacing functionality in compact designs.

2. Major Types & Functional Classification

Type	Functional Characteristics	Application Examples
Standard Shoulder Bushing Washer	Uniform wall thickness, concentric shoulder design	General-purpose machinery, automotive linkages
Threaded Shoulder Bushing	Integrated internal threading for secure fastening	Aerospace fastening systems, vibration equipment
Split Shoulder Bushing	Segmented design for easy installation/removal	Heavy equipment maintenance, shaft repair
Flanged Shoulder Washer	Extended flange for enhanced load distribution	Structural steel connections, rail systems

3. Structural Composition

Typical construction features:

Tapered or stepped outer diameter (15 -30 transition angle)
Controlled inside diameter tolerance ( 0.025mm to 0.1mm)
Material composition: Carbon steel (SAE 1045), Stainless Steel (AISI 304/316), Bronze (SAE 841), or Polymer (Nylon 6/66)
Surface treatments: Zinc plating (8-24 m), Black Oxide, DLC coating, or PTFE impregnation
Hardness range: 200-400 HV depending on application requirements

4. Key Technical Parameters

Parameter	Significance
ID/OD Dimensional Tolerance	Ensures proper fit with shaft and housing (typically H7/g6)
Shoulder Height	Determines axial positioning accuracy ( 0.1mm standard)
Hardness Rating	Affects wear resistance and load capacity
Surface Roughness (Ra)	Impacts friction coefficient (Ra 0.8-3.2 m typical)
Corrosion Resistance	Determines service life in harsh environments

5. Application Fields

Primary industries:

Automotive: Suspension systems, transmission linkages
Aerospace: Flight control actuation systems, engine mounts
Industrial Machinery: CNC machine tool spindles, robotic joints
Railway: Bogie pivot joints, coupler systems
Renewable Energy: Wind turbine pitch bearings, solar tracker mechanisms

6. Leading Manufacturers & Products

Manufacturer	Key Product Series	Technical Features
MISUMI	WSB Series	Modular design, 12 standard sizes
Nord-Lock Group	Shox Washer	Combined wedge-locking and bushing function
Bossard Group	Proliant SW	High-strength steel (12.9 class)
IKEUCHI	Oiles SPB	Self-lubricating polymer composite

7. Selection Guidelines

Key selection criteria:

Load Requirements: Calculate radial/axial loads using ISO 76:2006 standards
Environmental Factors: Consider operating temperature (-50 C to +300 C range)
Material Compatibility: Prevent galvanic corrosion between mating components
Installation Clearance: Allow 0.5-1.5mm radial play for thermal expansion
Case Study: In wind turbine pitch bearings, stainless steel shoulder washers with solid lubricant pockets demonstrated 40% longer service life versus conventional designs

8. Industry Trends

Emerging development directions:

Material innovation: Graphene-reinforced polymers for weight reduction
Smart integration: Embedded strain sensors for condition monitoring
Manufacturing advancement: Additive manufacturing for complex geometries
Sustainability focus: Bio-based coatings replacing hexavalent chromium
Standardization efforts: ISO/TC 2/SC 12 developing global design standards