5/16" Round Spacers (M-108)
5/16" round spacers are unthreaded cylindrical spacers with a clearance bore, sized to hold a 5/16" 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. The spacer fills the gap. The 5/16" body length sits directly between the common 1/4" and 3/8" sizes.
Round Spacers vs. Threaded Standoffs
A spacer has no threads. One bolt does all the clamping, passing through the clearance bore and fastening at each end of the stack. There's nothing to thread at the spacer itself, and no tool contact is needed at the spacer body.Threaded standoffs are used when individual mounting points require their own fastening, or when a board needs to be removed without disturbing the rest of the assembly. For a clean through-bolt setup, a spacer is simpler.
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Key Features
- Unthreaded clearance bore for pass-through bolt assembly
- 5/16" body length for intermediate clearance between 1/4" and 3/8"
- Round cylindrical body for a compact hardware footprint
- Available in aluminum and stainless steel
- Stainless steel offers strong corrosion resistance for harsh environments
- Aluminum is lightweight and non-magnetic
- Accommodates screws up to size 10
Applications for 5/16" Round Spacers
- PCB mounting
- Panel and bracket spacing
- Light mechanical assemblies requiring precise height separation
- Prototyping and R&D builds where standard sizes don't quite fit the design
Selection Guidance
- Spacer vs. Standoff: Use a spacer when a single bolt controls the full height gap. For independent threaded fastening at each mounting point, use a female or male-female standoff instead.
- Sizing: 5/16" is not a standard size the way 1/4" and 3/8" are. Before ordering, confirm that your layout genuinely requires this intermediate height. If 1/4" (M-107) or 3/8" (M-109) can work, those are more widely stocked.
- Material Selection: Aluminum suits lightweight builds where corrosion is not a concern. Stainless steel is the better choice for harsh environments or chemical exposure.
- Clearance Bore: Verify bore diameter against your fastener size before ordering. Full dimensional data is in the product listing.
