Bx-Flex Conduit Fitting, Screw On Type

Series No.	Part Number	Product Photo	KO Size (Inch)	Conduit Size (Inch)	Package/Box (Pcs)	Weight/Box (Kg)	Snap-In Structure	Certificate	Mated With
S31	S311-3/8		1/2	3/8	1200	8.2	V
S32	S3213-5/16		5/16	5/16	3000	4.5	V
S34	S3414-1/4		1/4	1/4	3000	4.5	V	-
S34	S341-3/8		1/2	3/8	3000	7.5	V
S33	S330-5/16		1/2	5/16	2500	15	V
S33	S331-3/8		1/2	3/8	2000	14	V

Frequently Asked Questions

What is the S31/S32/S33 screw-on conduit fitting?

The S31/S32/S33/S34 series are UL514B certified screw-on snap-in conduit fittings designed to connect flexible metal conduits to junction boxes, lighting fixtures, and lampshades. These fittings feature snap-in construction that allows quick push-to-fix installation while the metal flexible conduit screws in securely, providing reliable electrical protection.

What does "screw-on snap-in" design mean?

Screw-on snap-in means the fitting uses two installation methods: the fitting body snaps into the junction box knockout (push-to-fix), while the flexible metal conduit screws onto the fitting to create a secure mechanical and electrical connection. This hybrid approach combines quick installation ease with reliable conduit connection.

What are the differences between S31, S32, S33, and S34 series?

S31: Nylon body with steel snap part, -30℃~+105℃, UL certified. S32: Steel 65Mn body, -50℃~+200℃, UL/CSA certified. S33: Carbon steel Q235 body, -50℃~+300℃ (highest temperature), UL/CSA certified. S34: Similar to S32, -50℃~+200℃. Choose based on temperature requirements and environment.

What conduit sizes are available?

Available sizes include 1/4", 5/16", and 3/8" nominal conduit diameters, with corresponding 1/4", 1/2", and 1/2" knockout (KO) sizes. Multiple series and part numbers ensure compatibility with both small and standard conduit sizes for diverse lighting and junction box applications.

What conduits are these fittings compatible with?

These fittings are designed to mate with PRWG (galvanized steel round conduit) and PRWA (aluminum round conduit) series. They provide reliable connection for flexible metal conduits used in lighting fixtures, lampshade connections, and rectifier protection applications.

What is the temperature range for each series?

S31 operates -30℃~+105℃ (most limited range). S32 and S34 operate -50℃~+200℃ (moderate range). S33 operates -50℃~+300℃ (widest range for extreme high-temperature applications). This range variety allows selection based on specific installation environment requirements.

What is the IP rating?

All series (S31/S32/S33/S34) have IP40 rating, providing protection against solid objects larger than 1mm and splash water from any direction. This is appropriate for indoor lighting and junction box applications in commercial and industrial environments.

What certifications do these fittings hold?

S31 is UL certified per UL514B standards. S32/S34 are UL and Canadian CSA-C22.2 No.56 certified. S33 is CSA certified per the same standard. All hold UL/cUL/UL Recognized certifications (File No. E256570), ensuring North American electrical code compliance for lighting and junction box applications.

What material is used in each series?

S31: Nylon body with steel 65Mn snap part. S32/S34: Steel 65Mn body. S33: Carbon steel Q235 body. All materials are zinc-plated and RoHS compliant, providing corrosion resistance appropriate for lighting fixture and junction box environments.

Why is S33 ideal for high-temperature applications?

S33 features carbon steel Q235 body construction and operates -50℃~+300℃, the widest temperature range of all series. This makes it ideal for furnace areas, high-heat industrial locations, and other extreme-temperature lighting or wiring applications requiring superior thermal resistance.

How is installation performed?

Two-step installation: (1) Push the fitting body into the junction box knockout hole until it snaps in place (snap-in feature). (2) Screw the flexible metal conduit onto the fitting threads to create a secure connection. This simple process requires no special tools and provides quick assembly in the field.

What is the packaging quantity?

Packaging varies by series: S31 comes in 1200/box (8.2kg), S32/S34 in 3000/box (4.5-7.5kg), S33 in 2000-2500/box (14-15kg). The high quantities per box make these fittings economical for mass lighting fixture manufacturing and large commercial wiring projects.

What are typical applications?

These fittings are ideal for: lighting fixture connections, lampshade wire protection, rectifier connections, junction box conduit entries, commercial lighting installations, industrial LED fixture wiring, and any application requiring quick snap-in installation with screw-on conduit connection.

Is S31 nylon body suitable for all environments?

S31 with nylon body is suitable for controlled indoor environments with moderate temperatures (-30℃~+105℃). For outdoor, extreme-temperature, or chemically aggressive environments, S32 (steel, -50℃~+200℃) or S33 (carbon steel, -50℃~+300℃) are better choices.

Is RoHS compliance important?

Yes, all S31/S32/S33/S34 series are fully RoHS compliant, ensuring no hazardous substances like lead, mercury, or cadmium are used. This is important for lighting fixtures destined for environmentally-conscious markets and modern commercial applications.

How do these compare to push-in style fittings?

Screw-on fittings like S31-S34 provide stronger hold and more reliable electrical connection compared to push-in types. The screw connection ensures the conduit cannot accidentally disconnect under vibration or mechanical stress, important for lighting fixtures and high-reliability applications.

What tools are needed for installation?

Minimal tools required: just hand pressure to snap the fitting into the knockout, and a wrench or pliers to tighten the conduit screw connection. No power tools or special equipment needed, making field installation straightforward for electricians with minimal training.

Can grounding be achieved with these fittings?

Yes, when properly installed, the metal conduit screwed into the fitting provides continuity for equipment grounding. However, always verify local electrical codes, as some jurisdictions may require separate grounding conductors for certain lighting and wiring applications.

Why choose S32 or S34 over S31?

S32/S34 offer superior advantages: extended temperature range (-50℃~+200℃ vs -30℃~+105℃), steel body for greater durability, CSA certification in addition to UL, and better performance in harsh industrial environments. The extra durability justifies the slightly higher cost for demanding applications.

Can custom specifications be ordered?

Yes, custom configurations are available for special lighting fixture and industrial projects. Contact our sales team at info@flexible86.com or +86-563-6636999 to discuss bulk orders, custom sizes, and project-specific material or temperature requirements.