Board Spacers, Standoffs

Part Number	Description / PDF	Quantity
M2121-3005-SS-20 RAF	4.5MM HEX X 28MM X M3 THD	150
NAS1831C4C19 RAF	STAINLESS STEEL 1/4 HEX FEMALE S	202
NAS1831C3A04 RAF	STAINLESS STEEL 3/16 HEX FEMALE	109
M2148-3005-B RAF	6MM HEX X 13MM X M3 THD	0
M2140-4007-SS RAF	6MM HEX X 5MM X M4 THD	457
M1304-3005-N RAF	6MM HEX X 7MM X M3 THD	500
1125-4-AL RAF	ROUND SPACER ALUMINUM 5/16"	2733
NAS1829A4G36 RAF	ALUMINUM 1/4 HEX MALE/FEMALE STA	0
1539-C-6-AL RAF	1/4 RD X 5/8 X .140 ID	600
M2142-3005-AL RAF	6MM HEX X 7MM X M3 THD	950
4575-832-SS-20 RAF	5/16 HEX X 1/2 LENGTH	100
4530-632-S-12 RAF	HEX STANDOFF #6-32 STEEL 1/4"	1608
1184-12-S-12 RAF	3/8 RD X 1/8 X 0.218	500
NAS1831C4B12 RAF	STAINLESS STEEL 1/4 HEX FEMALE S	0
1163-10-AL RAF	5/16 RD X 3/4 X .192 ID	521
1218-10-AL RAF	1/2 RD X 5/16 X .192 ID	400
2101-832-N RAF	1/4 HEX X 5/16 LENGTH	50
NAS43DD5-100A RAF	ALUMINUM UNTHREADED SPACER 7/16	0
1681-632-N RAF	1/4 RD X 5/16 LENGTH	288
2246-632-N RAF	3/8 HEX X 1.00 LENGTH	200

Board Spacers, Standoffs

1. Overview

Board spacers and standoffs are specialized hardware components used to create controlled spacing between printed circuit boards (PCBs), panels, or structural elements. They provide mechanical support, electrical isolation, and thermal management in electronic assemblies. Their importance in modern technology includes enabling compact designs, reducing vibration stress, and improving heat dissipation in devices ranging from smartphones to industrial control systems.

2. Main Types & Functional Classification

Type	Functional Features	Application Examples
Cylindrical Spacers	Simple tubular design with uniform diameter	PCB layer separation in consumer electronics
Hexagonal Standoffs	6-sided structure for wrench tightening	Industrial equipment panel mounting
Self-clinching Standoffs	Permanent installation with threaded compression	Sheet metal enclosures in servers
Adjustable Spacers	Variable length through threaded adjustment	Prototype development and testing
Insulated Spacers	Non-conductive materials for electrical isolation	High-voltage power supply assemblies

3. Structure & Composition

Typical construction includes:

Material: Stainless steel (corrosion resistance), aluminum (lightweight), or nylon (insulation)
Geometry: Cylindrical (standard), stepped (for multiple board heights), or flanged (for load distribution)
Installation Features: Internal threading (male/female), knurled surfaces (for grip), or press-fit tabs
Surface Treatment: Passivation (metal), UV resistance (plastics), or EMI shielding coating

4. Key Technical Specifications

Parameter	Importance
Material Hardness (HV)	Determines wear resistance and load capacity
Thread Engagement Length	Affects vibration resistance in dynamic environments
Thermal Conductivity (W/m K)	Critical for heat dissipation in power electronics
Dielectric Strength (kV/mm)	Safety factor in high-voltage applications
Installation Torque Rating	Prevents over-tightening damage to PCBs

5. Application Fields

Primary industries include:

Electronics Manufacturing: Server racks, LED displays
Automotive: Engine control units (ECUs), ADAS systems
Aerospace: Satellite PCB mounting, avionics enclosures
Medical Devices: MRI scanner internal structures
Consumer Electronics: Smartphone PCB stacking

6. Leading Manufacturers & Products

Manufacturer	Representative Product
PEM	S-8900 Series self-clinching standoffs
RS Components	486-8826 insulated hexagonal spacers
Mouser Electronics	925206-12 adjustable PCB spacers
McMaster-Carr	91285A102 stainless steel standoffs

7. Selection Recommendations

Evaluate mechanical load requirements vs material strength
Match thread type (UNC/UNF/Metric) with assembly hardware
Consider CTE (Coefficient of Thermal Expansion) compatibility with PCB materials
Select insulated variants for >50V circuits
Use vibration-damping coatings in mobile applications

8. Industry Trends

Emerging developments include:

Miniaturization: Sub-1mm spacers for wearable devices
Material Innovation: Conductive polymer composites for EMI shielding
Smart Integration: Standoffs with embedded strain gauges for structural monitoring
Automated Installation: Self-aligning designs for robotic assembly lines
Sustainability: Biodegradable plastic options (PLA-based) entering mainstream production