RJT-13H Sanitary Hexagonal Union Nut with Whitworth Thread in SS304 / SS316L

Component Role & RJT Whitworth-Thread Hex Design

The RJT-13H hexagonal nut is the standard wrench-tightened retaining collar for Ring Joint Type (RJT / BS 4825-5) sanitary pipe unions. Its internal rear flange captures the shoulder of an RJT-14 welding liner while its internal Whitworth threads engage an RJT-15 male part to compress the O-section RJT union ring.

Material Grades & Dual-Source Dimensional Scope

Supplied in SS304 and SS316L stainless steel across six nominal sizes from 1.0" through 4.0" (1.0", 1.5", 2.0", 2.5", 3.0", and 4.0"), the dimensional drawing specifies 8 TPI Whitworth threads from 1.0" to 2.0" (42.266×8TPI WHIT to 69.256×8TPI WHIT) and 6 TPI Whitworth threads from 2.5" to 4.0" (81.956×6TPI WHIT to 118.720×6TPI WHIT), with uniform 22.2 mm height H, bore A from 33.3 mm to 109.5 mm, and hex flats SW from 50.8 mm to 130.2 mm. Secondary datasheet records (304 grade, codes RJTHN25 to RJTHN100) corroborate the 1"–4" series.

Source Text Note & Ordering Guidance

Although the page summary list prints 'Shape: Round' and its intro prose contains a copy-over paragraph mentioning SMS unions, the product title, photograph, and dimensional drawing confirm a hexagonal RJT-13H nut with across-flats dimension SW. Specify nominal RJT size and alloy grade when ordering.