Washers - Bushing, Shoulder

Part Number	Description / PDF	Quantity
12SWS0433 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	4990
MNI-10-8 Richco, Inc. (Essentra Components)	WASHER SHOULDER #10 NYLON	716
16CW004040 Richco, Inc. (Essentra Components)	CUPPED WASHER, #4 SCREW, .115 ID	7930
12SWS0604 Richco, Inc. (Essentra Components)	SHOULDER WASHER .160 ID .300 OD	783
MNI-4-3 Richco, Inc. (Essentra Components)	WASHER SHOULDER #4 NYLON	4793
12SWS1221 Richco, Inc. (Essentra Components)	SHOULDER WASHER .260 ID .630 OD	1490
B-435-V2325 Aearo Technologies, LLC – a 3M company	BUSHING 1/2" THERMOPLASTIC	0
12SWS0423 Richco, Inc. (Essentra Components)	SHOULDER WASHER .116 ID .250 OD	1000
3236 Keystone Electronics Corp.	WASHER SHOULDER #8 FIBRE	949513900
FB1650A Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL,.765 IN	2000
12SWS0835 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	9482
MNI-6-12 Richco, Inc. (Essentra Components)	WASHER SHOULDER #6 NYLON	2899
12SWS0627 Richco, Inc. (Essentra Components)	SHOULDER WASHER .170 ID .365 OD	945
11SFW0008 Richco, Inc. (Essentra Components)	FINISHING WASHER .171 ID .510 OD	1000
12SWS1017 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	4984
FBM1000A Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL,.197 IN	2000
12SWS2573 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	3500
12SWS1243 Richco, Inc. (Essentra Components)	SHOULDER WASHER .437 ID .630 OD	960
FB1660A Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL,1.000 I	1283
12SWS0426 Richco, Inc. (Essentra Components)	SHOULDER WASHER .115 ID .250 OD	1000

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