Stainless Steel Flanges

Sizes: 1/2” to 4”
Connections: Threaded, Socket Weld, Slip-On, Blind

Stainless steel flanges are the go-to choice for corrosion resistance and dependable pipe connections in industrial and commercial piping. We supply 304 and 316 stainless steel flanges in common, job-ready sizes from 1/2” through 4”, with connection styles that fit everyday installs and maintenance needs.

Choose from threaded, socket weld, slip-on, and blind stainless flanges. If you’re matching an existing line, replacing a flange, or building a new section of piping, we can help confirm the correct material, size, and connection style so you avoid delays and rework.

Quick Specs

Materials: 304 Stainless Steel, 316 Stainless Steel
Sizes: 1/2”, 3/4”, 1”, 1-1/4”, 1-1/2”, 2”, 2-1/2”, 3”, 4”
Connections: Threaded, Socket Weld, Slip-On, Blind

What Is a Stainless Steel Flange?

A stainless steel flange is a fitting used to connect piping to piping, valves, pumps, and other equipment using bolts and a sealing surface. Flanges make systems easier to assemble, service, and modify—especially when you need future access for inspections, maintenance, or upgrades.

Stainless steel is commonly used for flanges because it holds up well in environments where corrosion is a concern. In many systems, choosing the right stainless grade and connection style is just as important as selecting the correct size.

How to Choose the Right Stainless Flange

Step 1 — Choose Your Grade: 304 vs 316

304 Stainless: A strong, general-purpose option for many industrial environments where corrosion exposure is moderate.

316 Stainless: Better corrosion resistance in harsher conditions—especially where salt, chlorides, or chemical exposure are a factor.

If you’re installing near coastal air, washdown areas, or chemical environments, 316 is often the safer long-term choice.

Step 2 — Choose the Connection Type

Threaded: No welding; faster install; commonly used on smaller piping

Socket Weld: Strong welded connection for smaller sizes; compact design

Slip-On: Easier alignment during fit-up; welded installation

Blind: Seals the end of a line for maintenance access or future expansion

Step 3 — Confirm the Size You Need

Stainless flanges are typically matched to the nominal pipe size. If you’re replacing an existing flange, confirm the size from documentation or markings, then verify the connection type so the replacement mates correctly.

Stainless Flange Types We Offer

Threaded Stainless Steel Flanges

Threaded flanges are a practical choice when you want a removable connection without welding. They’re commonly used on smaller piping where installation speed matters and welding isn’t ideal.

Best for: Quick installs, serviceability, smaller lines
Good to know: Confirm thread compatibility and sealing approach before ordering.

Socket Weld Stainless Steel Flanges

Socket weld flanges are designed for smaller diameter piping where a strong, leak-resistant welded joint is preferred. The pipe is inserted into the socket and welded around the joint.

Best for: Smaller lines, stronger welded joints
Good to know: Requires welding; often selected where vibration or stress is a concern.

Slip-On Stainless Steel Flanges

Slip-on flanges slide over the pipe and are welded in place. They’re often chosen because alignment is typically easier during installation.

Best for: Easier fit-up, general piping installs
Good to know: Welded installation; confirm the connection style matches your system.

Blind Stainless Steel Flanges

Blind flanges close off a pipeline or opening. They’re often used as isolation points for maintenance, pressure testing, inspections, or future tie-ins.

Best for: Isolation points, maintenance, future expansion
Good to know: A simple way to add service access without redesigning the line later.

Stocked Sizes (1/2”–4”)

We stock stainless steel flanges in common small-to-mid piping sizes used across industrial and commercial systems. If you’re matching an existing system, send the details and we’ll help you confirm the correct fit.

304 vs 316 Stainless Steel — Quick Comparison

Choosing between 304 and 316 is usually about the environment. Both grades are widely used in industrial piping, but 316 is typically preferred when corrosion risk is higher—especially in chloride-heavy conditions like salt exposure, coastal air, and frequent washdowns.

304 vs 316 Comparison Table

Common Applications

Stainless steel flanges are used anywhere corrosion resistance and serviceability matter. They’re common in:

• Water and wastewater piping systems
• Manufacturing and process piping where durability is important
• Washdown environments where corrosion risk is higher (often a 316 fit)
• Coastal or marine-adjacent facilities where salt exposure is common
• General industrial maintenance where quick replacement and consistent fit matter

If you tell us where the flange will be installed, we can help you decide whether 304 or 316 makes the most sense for the long term.

Mistakes to Avoid When Ordering Stainless Flanges

• Picking 304 when the environment really calls for 316 (salt/chlorides/washdowns)
• Choosing the correct size but the wrong connection style (threaded vs weld)
• Not confirming what you’re mating to (existing connection style and sealing approach)
• Skipping the maintenance plan (blind flanges can save major time later)
• Ordering without a simple spec list (size, grade, connection, quantity)

A quick spec confirmation upfront prevents delays, rework, and returns. If you’re replacing an existing part, send what you know and we’ll help you match it accurately.

Ordering Checklist

Send the details below and we’ll quote the correct flange quickly:

• Size (NPS):
• Material: 304 or 316
• Connection type: Threaded / Socket Weld / Slip-On / Blind
• Quantity:
• Environment / application (optional): indoor, washdown, coastal, chemical, etc.
• Need-by date / ship-to ZIP:

Frequently Asked Questions

1) What’s the difference between 304 and 316 stainless steel flanges?

The main difference is corrosion resistance. 304 stainless is a strong, general-purpose choice for many environments with moderate exposure. 316 stainless typically performs better in harsher conditions, especially where salt, chlorides, coastal air, or washdowns are common. If the installation sees aggressive moisture or chemicals, 316 is often the safer long-term option.

2) When should I choose 316 over 304?

Choose 316 when corrosion risk is higher—coastal locations, washdown areas, or environments with chlorides and certain chemicals. In those conditions, 316 generally lasts longer and helps reduce premature corrosion issues. For clean indoor service, 304 often works; for harsh exposure or long-term reliability, 316 is usually worth it.

3) What is a threaded stainless flange used for?

A threaded flange connects to a threaded pipe without welding. It’s often used on smaller piping where installation speed and removability matter. Threaded flanges can be practical for maintenance-heavy systems because the connection can often be removed without cutting and rewelding. Confirm the thread type and sealing approach before ordering.

4) What is a socket weld flange used for?

A socket weld flange is commonly used on smaller piping when you want a strong, leak-resistant welded connection. The pipe fits into a socket and is welded around the joint. Socket weld flanges are often selected where reliability matters, including systems with vibration or pressure changes. Because welding is required, they’re best for installations equipped for proper weld procedures.

5) What is a slip-on flange used for?

A slip-on flange slides over the pipe and is then welded in place. Many installers choose slip-on flanges because fit-up and alignment are typically easier. They’re commonly used for general piping systems where a welded connection is desired. Confirm the connection style matches your line and that the system is set up for welding and proper sealing.

6) What is a blind flange used for?

A blind flange closes off the end of a pipe or an opening in a system. It’s commonly used to create isolation points for maintenance, pressure testing, inspections, or future expansion. Adding blind flanges in the right places can save time later because you can access or modify the system without cutting into piping.

7) Do stainless steel flanges require a gasket?

Most flanged connections use a gasket or sealing method to create a tight seal between mating surfaces. The exact gasket depends on the connection style and service conditions. Stainless flanges work with many gasket materials, but it’s important to match the gasket to temperature, pressure, and chemical exposure requirements.

8) How do I confirm the correct flange size?

The most reliable way is to confirm the nominal pipe size (NPS) from documentation or existing component markings. If you’re replacing a flange, verify both size and connection style so the replacement mates correctly. If you’re unsure, share the size details and we’ll help you confirm the right flange for your line.

9) Can stainless steel flanges be used with carbon steel pipe?

Yes, stainless flanges are often used in systems that include carbon steel piping, depending on the application and corrosion plan. In mixed-material systems, confirm compatibility for the environment and account for corrosion considerations—especially in wet or corrosive conditions. Share what you’re mating to and the environment, and we can help with grade selection.

10) What information do you need to quote stainless steel flanges quickly?

For a fast quote, provide size (NPS), material (304 or 316), connection type (threaded, socket weld, slip-on, blind), and quantity. If you can add the application environment and your need-by date, it helps confirm the best match and availability. If replacing a part, a photo or markings can speed things up further.

Ready to order or need help matching an existing flange?

Send your size, grade (304/316), connection type, and quantity. We’ll help you choose the right stainless flange the first time—so your install goes smoothly and your system stays dependable.