Product Overview
The SFS 5610:2024 Figure NA.15 Interchangeability Gauge is a Finnish national test gauge specified in Annex NA of SFS 5610:2024 – the Finnish national standard for plugs and socket-outlets for household and similar general purposes. It applies to a 16 A 250 V two-pole plug without protective (earthing) contact – in the original Finnish wording: “16 A 250 V kaksinapainen pistotulppa ilman suojakosketinta”.
The caption of the standard drawing reads: “Kuva NA.15 TulkkI, jolla todetaan, etteivät pistotulpat ole vaihtokelpoisia suojakosketinpistotulppien kanssa” – “Figure NA.15: Gauge with which it is verified that plugs are not interchangeable with plugs having protective contacts.” The gauge therefore verifies the non-interchangeability requirement between the different plug/socket-outlet systems used in Finland.
Requirements Stated in the Standard Drawing (Selite)
- “A Liikkuvat suojakoskettimet.” – Item A = movable protective contacts (side earthing contacts).
- “Suojakoskettimien etäisyys toisistaan lepoasennossa on 29 mm ± 0,01 mm. Kun suojakoskettimet on erotettu 32 mm etäisyydelle toisistaan, on molempien kosketinpaine 5 N.” – The distance between the protective contacts in the rest position is 29 mm ± 0,01 mm; when they are separated to a distance of 32 mm, the contact force of each is 5 N.
- “Ei saa olla mahdollista työntää tulppaan ilman suojakosketinta olevaa pistotulppaa.” – It shall not be possible to insert a plug without a protective contact into the gauge.
Model Number
SC-SFS5610-NA15
Technical Parameters
| Item | Dimension / Requirement |
|---|---|
| Applicable plug | 16 A 250 V, two-pole, without protective contact |
| Pin centre distance | 19 ± 0,05 mm |
| Slot width (top section) | 5,1 ± 0,01 mm |
| Section height (top) | 5,4 −0,01 / 0 mm |
| Corner radius (top) | R = 1 +0,1 / 0 mm |
| Recess diameter | Ø40 ± 0,03 mm |
| Protective-contact opening width | 33,5 ± 0,03 mm |
| Contact opening distance | 22 ± 0,3 mm |
| Side contour | 5,5 ± 0,03 mm; R = 3,8 ± 0,03 mm; R = 0,5 +0,1 / 0 mm |
| Top slot | 1,0 ± 0,3 mm |
| Overall length / height | 37 mm / 45 mm |
| Protective contacts at rest | 29 mm ± 0,01 mm apart |
| Contact force at 32 mm separation | 5 N per contact |
| Body | Solid machined steel gauge block, model stamped on the side |
All dimensions are taken from the SFS 5610:2024 Kuva NA.15 standard drawing; the drawing shall prevail in case of any discrepancy.
Standard Drawing

Product Pictures




