SO Self-Clinching Through Standoff – SO, SOS, BSO Types | Helefastener

Helefastener SO self-clinching standoffs provide permanent, flush-mounted male-female threads in thin sheet metal for stacking PCBs, mounting boards and spacing assemblies. The clinch end presses into the panel and locks without welding; the through thread receives a screw from either side. Standard types are SO, SOA, SOS and SO4 (metric, through-hole), with BSO blind standoffs available when the reverse side of the sheet must stay clean.

SO through standoffs – metric, clinch mount.

Specifications

Parameter	Value
Types	SO (thru), SOA, SOS (thru, closed end), SO4; BSO blind type available
Example model	SO-M3-10ZI: M3 × 0.5 thread, min. sheet 1.02 mm, hole size 4.22 mm
Size range	M3–M5 standard; other sizes on request
Materials	Steel (zinc plated), stainless steel, aluminium, brass
Length	Standard lengths per type chart; custom lengths on request

Choosing between SO, SOS and BSO

SO suits general board stacking where both thread ends are used. SOS closes the standoff end, keeping fasteners and contaminants out of the internal thread. BSO is the blind choice: the clinch side stays solid, which matters when the reverse face is a visible or gasketed surface. For compact electronics, our micro and surface-mount (SMTSO) standoffs cover reflow and tight-pitch layouts.

Send panel thickness, hole size and required length through the quote form or WhatsApp – we will confirm type, part number and lead time (stock items dispatch in 3–7 days; free samples ship freight collect).