Washers - Bushing, Shoulder

Part Number	Description / PDF	Quantity
FB1530A Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL,.380 IN	3996
MNI-M2.5-1.3 Richco, Inc. (Essentra Components)	WASHER SHOULDER M2.5 NYLON	0
11SFW0010B Richco, Inc. (Essentra Components)	FINISHING WASHER .196 ID .575 OD	0
12SWS2559 Richco, Inc. (Essentra Components)	SHOULDER WASHER .385 ID .750 OD	500
16CW006040 Richco, Inc. (Essentra Components)	CUPPED WASHER, #6 SCREW, .140 ID	9790
12SWS0434 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	3380
MNI-HT-4-220 Richco, Inc. (Essentra Components)	WASHER SHOULDER #4 POLY SULFIDE	3662
12SWS0230 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	4295
12SWS0425 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	4580
12SWS0436 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	7379
10SC010025 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	24865
12SWS0920 Richco, Inc. (Essentra Components)	SHOULDER WASHER .217 ID .413 O	0
12SWS0848 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	9000
12SWS3619 Richco, Inc. (Essentra Components)	SHOULDER WASHER .250 ID 1.000	0
12SWS0910 Richco, Inc. (Essentra Components)	SHOULDER WASHER .191 ID .438 O	0
10SC006009 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	14965
12SWS0937 Richco, Inc. (Essentra Components)	SHOULDER WASHER .240 ID .480 O	0
12SWS1157 Richco, Inc. (Essentra Components)	SHOULDER WASHER .252 ID .375 O	0
12SWS0200 Richco, Inc. (Essentra Components)	SHOULDER WASHER, NATURAL, NYLON	2850
12SWS0179 Richco, Inc. (Essentra Components)	SHOULDER WASHER .024 ID .181 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