3/8" Round Spacers (M-109)
3/8" round spacers are unthreaded cylindrical spacers with a clearance bore, sized to hold a 3/8" gap between PCBs, panels, and chassis surfaces. A bolt passes through the body and threads into a nut or tapped hole at the other end. Nothing engages the spacer itself; it just holds the gap.
The 3/8" body length is a practical step up from the common 1/4" size. It works well when through-hole component leads, taller connectors, or cable routing beneath the board need more room than 1/4" provides.
The 3/8" body length is a practical step up from the common 1/4" size. It works well when through-hole component leads, taller connectors, or cable routing beneath the board need more room than 1/4" provides.
Round Spacers vs. Threaded Standoffs
With a spacer, one bolt does the clamping for the whole assembly. It passes through the clearance bore and fastens at each end. No threads in the spacer body, no tool contact at the spacer itself. Assembly is straightforward.When each mounting point needs its own independent fastening, or when the design requires removing a single board without disturbing the rest, threaded standoffs are the right call. For a simple through-bolt setup, a spacer gets the job done with less hardware.
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Key Features
- Unthreaded clearance bore for pass-through bolt assembly
- 3/8" body length for moderate-to-tall board clearance
- Round cylindrical body for a compact hardware footprint
- Available in aluminum and stainless steel
- Stainless steel offers strong corrosion resistance for demanding environments
- Aluminum is lightweight and non-magnetic
- Accommodates screws up to size 10
Applications for 3/8" Round Spacers
- PCB mounting where through-hole components or connectors require more than 1/4" clearance
- Panel and bracket spacing in enclosures and control systems
- Light mechanical assemblies requiring moderate height separation
- Prototyping and R&D builds where clearance requirements exceed standard 1/4" sizing
Selection Guidance
- Spacer vs. Standoff: Use a spacer when a single bolt controls the full height gap. For designs where each mounting point needs its own threaded connection, use a female or male-female standoff.
- Sizing: 3/8" sits between the common 1/4" (M-107) and the tallest standard option, 1/2" (M-110). If 1/4" isn't quite enough room and 1/2" is more than the layout needs, 3/8" is likely the right fit. Check the 5/16" (M-108) if you need something in between.
- Material Selection: Aluminum is a good fit for lightweight builds where corrosion is not a concern. Stainless steel is the better choice for harsh environments or applications with chemical exposure.
- Clearance Bore: Verify bore diameter against your fastener size before ordering. Full-dimensional data is in the product listing.
