Ask a research-administration question
Answers are drawn from CASRAI and the rest of the CASRAI corpus, with a link to every source.
Answers are AI-generated from CASRAI’s own published pages and can be wrong, so check the linked sources before relying on one; your question is logged without personal data — never sold, never used to train a third-party model — to show us what CASRAI is missing, so please do not type personal or confidential details. How we use this
CASRAI is the reference for research administration — bookmark it for the next question.
Superlok
Superlok Compression Ferrule Set - SFS
$4.99 - $7.99
In stockPrice varies by Size.
Superlok SFS ferrule set in 316 stainless for fractional-inch tube, in 1/4, 3/8 and 1/2 in (SFS-4, SFS-6, SFS-8). Superlok’s tube fittings use a front ferrule and a rear ferrule working together inside the nut, and this set is the replacement pair. The supplier lists it as interchangeable with other major fractional compression brands including Parker, Swagelok and DK-Lok.
Choose Size to continue.
Buying through procurement?
Generate a formal quotation for 1 × this item, plus our W-9 — everything your finance department needs to raise a purchase order.
Choose Size to continue.
Description
The Superlok SFS is the ferrule set for Superlok fractional-inch compression tube fittings, supplied in 316 stainless. Three sizes are listed, sized by tube outside diameter: SFS-4 for 1/4 in tube, SFS-6 for 3/8 in and SFS-8 for 1/2 in.
Superlok fittings are a four-piece design — body, front ferrule, rear ferrule and nut. The nut drives the two ferrules onto the outside diameter of the tube when the fitting is first pulled up, and the ferrules deform to grip and seal against it. That deformation is why ferrules are stocked as a replacement item in their own right: the body and nut survive a rework, the ferrules have already taken a set.
The supplier lists the SFS set as interchangeable with the other major fractional compression brands it names — Parker, Swagelok and DK-Lok. That is the manufacturer’s claim, not an independent test result; if a mixed-brand joint matters to your qualification paperwork, confirm it against the fitting body you actually hold before you build the run.
The matching nut is the Superlok SN series and is listed separately.
Frequently asked questions
What is in the set?+
A front ferrule and a rear ferrule, which is the pair Superlok's four-piece fitting design uses inside the nut. The nut itself is the separate SN series.
What sizes are available?+
Three, sized by tube outside diameter: SFS-4 (1/4 in), SFS-6 (3/8 in) and SFS-8 (1/2 in).
What material is it?+
316 stainless steel, as stated in the supplier's own description of the SFS set.
Will it fit another brand's fitting body?+
The supplier lists the SFS set as interchangeable with fractional tube fittings from Parker, Swagelok and DK-Lok. We are repeating that as the manufacturer's claim rather than making it ourselves — verify against the specific body you hold if the joint is going into a qualified or documented system.
Why would I buy ferrules on their own?+
Ferrules seal by deforming permanently onto the tube outside diameter as the fitting is pulled up. Once set they belong to that piece of tube, so reworking or re-terminating a line normally means a fresh set even when the body and nut are reusable.
Is the nut included?+
No. This listing is the ferrule set only. The Superlok SN compression nut is a separate listing in 1/4, 3/8 and 1/2 in.
