You’ve selected the right grade. You’ve specified the correct schedule. The metallurgy meets your requirements, and the heat treatment aligns with your application. Then the pipe arrives at your job site, and someone asks: “What do we do with these ends?”
That question—how pipes connect to each other and to fittings—determines everything about installation speed, joint integrity, and long-term reliability. And it all starts with how the pipe ends were finished at the mill.
At Tianjin Xiangliyuan Steel, we’ve shipped millions of meters of pipe to projects across five continents. Every order includes a specification for end finish, and every end finish serves a purpose. Some clients want plain ends for field welding. Others need bevels ready for immediate joint completion. Still others require threaded connections for rapid assembly in remote locations.
Understanding these options—and choosing correctly—saves time, money, and frustration during construction.
This guide explains the three most common pipe end finishes, when to specify each, and what standards govern their preparation. Whether you’re designing a cross-country pipeline or a local water system, getting the ends right matters.
For detailed specifications or to discuss your end finish requirements, visit https://www.xlysteel.com/ or contact our team at infosteel@xlygt.com.
Why Pipe End Finishes Matter
Imagine assembling a piping system where every joint requires hours of additional preparation. Each pipe end needs cutting to square, beveling for welding, or threading field-cut threads. Labor costs multiply. Schedules slip. Quality suffers because field conditions rarely match mill precision.
That’s why end finishes exist. They move preparation from the field to the mill, where controlled conditions, specialized equipment, and trained operators produce consistent, code-compliant results.
The right end finish:
Reduces field labor – Mill-prepared ends arrive ready for installation
Ensures quality – Precision machining beats field grinding every time
Speeds construction – Pipes connect faster when ends need no additional work
Improves joint integrity – Properly prepared ends make better welds and seals
Simplifies procurement – Clear specifications eliminate confusion
Now let’s examine each option.
Plain End: The Versatile Standard
What is a plain end pipe?
A plain end pipe is exactly what it sounds like: the pipe ends are cut square, with no additional preparation. The cut should be clean, free of burrs, and perpendicular to the pipe axis within specified tolerances.
How plain ends are made
At the mill, plain ends typically come from the cutting process itself. Saw cuts, torch cuts, or shear cuts produce the initial pipe length. For plain end specifications, these cuts must meet requirements for:
Squareness – The end should be perpendicular to the pipe axis, typically within 1.5mm for most specifications
Burr removal – Sharp edges or raised material from cutting must be removed to prevent injury and interference
Surface condition – The cut area should be free of cracks, laminations, or other defects
Some applications specify “plain end beveled” or “plain end squared” to clarify the exact requirement.
When to specify plain ends
Plain ends suit several situations:
Field welding with custom bevels. Some contractors prefer to cut their own bevels based on specific welding procedures. Plain ends give them maximum flexibility.
Mechanical couplings. Products like Victaulic or other grooved couplings often work best with plain ends that receive field-cut grooves.
Structural applications. When pipes serve as columns, bracing, or other structural elements, plain ends often connect through base plates or other fittings requiring square cuts.
Socket weld connections. For smaller diameters, socket weld fittings accept plain end pipe.
Pipe that will be cut again. If your installation requires cutting pipes to non-standard lengths anyway, mill-prepared ends may be unnecessary.
Standards for plain ends
Plain end requirements appear in most pipe specifications:
ASTM A53/A106 – Both specify permissible variations in end squareness
API 5L – Section 9 addresses end finishes, including plain ends
ASME B16.25 – While primarily for bevels, it also addresses end preparation
Typical tolerances require the end to be square within 1.5mm (1/16 inch) for most sizes.
Advantages of plain ends
Maximum flexibility for field modifications
Lowest cost option
Suitable for multiple connection methods
Readily available from stock
Disadvantages
Field beveling adds labor and equipment costs
Quality of field-prepared ends varies with worker skill
Additional inspection may be needed
Beveled End: Ready for Welding
What is a beveled end pipe?
A beveled end pipe features an angled cut at the pipe end, typically 30 to 37.5 degrees, leaving a narrow flat land at the tip. This bevel prepares the pipe for butt welding, providing the proper geometry for complete joint penetration.
How bevels are made
Beveling requires machining—either on a dedicated beveling machine or as part of the cutting process. Modern pipe mills use:
Beveling attachments on saws – Combining cutting and beveling in one operation
Standalone beveling machines – For precise control of angle and land dimensions
Portable beveling tools – For field touch-up when needed
The bevel geometry includes several elements:
Bevel angle. Typically 30 degrees for standard wall pipes, but can range from 22.5 to 37.5 degrees depending on wall thickness and welding procedure.
Root face (land). A small flat area at the tip of the bevel, typically 1.6mm (1/16 inch) ± 0.8mm. This land prevents burning through during the root pass.
Included angle. The total angle between the two prepared faces when pipes are butted together. For 30-degree bevels on each pipe, the included angle is 60 degrees.
ASME B16.25 governs bevel geometry for most applications, providing standard dimensions for different wall thicknesses.
When to specify beveled ends
Beveled ends are the default choice for:
Butt-welded piping systems. Most process piping, pipeline construction, and pressure systems use butt welding, which requires beveled ends.
Heavy wall pipe. As wall thickness increases, proper bevel geometry becomes essential for complete fusion.
Critical service applications. When weld quality matters most, mill-prepared bevels provide better consistency than field preparation.
High-pressure pipelines. API 5L line pipe for oil and gas transmission almost always ships with beveled ends.
Radiographed welds. If welds will undergo radiographic inspection, proper bevel geometry helps ensure sound welds that pass examination.
Standards for beveled ends
Multiple standards govern bevel geometry:
ASME B16.25 – The primary standard for butt-welding ends, covering bevel angle, root face, and tolerances
API 5L – Specifies bevel geometry for line pipe, generally following ASME B16.25
ASTM A53/A106 – Reference ASME B16.25 for bevel details when specified
ISO 6761 – International standard for pipe end preparation
Advantages of beveled ends
Ready for welding immediately upon arrival
Consistent geometry improves weld quality
Eliminates field beveling labor and equipment
Reduces risk of improper preparation
Speeds construction schedule
Disadvantages
Higher cost than plain ends
Less flexibility if field conditions require different bevel angles
Must protect bevels during handling and storage
Special bevel configurations
Some applications require modified bevels:
Compound bevels. For very thick walls, a compound bevel (J-bevel or U-bevel) reduces the amount of weld metal needed while maintaining proper access to the root.
Bevel with backing ring. Some designs incorporate a backing ring, requiring modified bevel geometry.
Internal bevel. For pipes requiring internal smoothness, internal bevels may be specified.
At Tianjin Xiangliyuan Steel, our beveling equipment produces precise geometries meeting ASME B16.25 requirements. We can accommodate special bevel configurations for specific project needs. Visit https://www.xlysteel.com/ to discuss your bevel requirements.
Threaded End: Mechanical Connection
What is a threaded end pipe?
A threaded end pipe has threads cut into its ends, allowing mechanical connection to threaded fittings, couplings, or other threaded pipes. Threads provide a removable joint suitable for many services.
How threads are made
Threading requires cutting the thread form into the pipe wall. Methods include:
Die cutting. The pipe rotates against stationary dies that cut the thread form. Common for smaller diameters and field threading.
Thread rolling. For some applications, threads can be formed rather than cut, though cutting remains more common for pipe.
CNC threading. Modern mills use computer-controlled threading machines for precise, consistent threads.
The thread form itself follows strict standards:
Tapered threads. Most pipe threads are tapered—the diameter decreases along the thread length. This taper creates a wedge fit when joints are made up, providing both mechanical strength and a seal.
Thread form. The shape of each thread—the angle, depth, and pitch—follows national or international standards.
Length of thread. Enough thread length must be provided to engage fully with mating fittings.
When to specify threaded ends
Threaded ends suit specific applications:
Small diameter piping. Typically 2 inches and smaller, though larger sizes can be threaded.
Non-critical services. Water, air, low-pressure steam, and other non-hazardous fluids.
Systems requiring disassembly. Threaded joints can be taken apart, unlike welded connections.
Remote locations. Threading requires less equipment and skill than welding.
Temporary or frequently modified systems. Threaded connections facilitate changes.
Standards for threaded ends
Thread standards vary by region and application:
ASME B1.20.1 – The standard for American National Standard Taper Pipe Threads (NPT)
API 5B – Specification for threading, gauging, and thread inspection of casing, tubing, and line pipe threads
ISO 7-1 – International standard for pipe threads where pressure-tight joints are made on the threads
ISO 228-1 – International standard for pipe threads where pressure-tight joints are not made on the threads
NPT (National Pipe Taper) dominates in North America. Key characteristics include:
Taper of 1 in 16 (3/4 inch per foot)
60-degree thread angle
Truncated crests and roots
Designed to seal by thread deformation during make-up
API threads for oilfield applications include:
API Round Thread – For casing and tubing
API Buttress Thread – For high-tensile casing connections
API Extreme Line – For special clearance connections
When NOT to specify threaded ends
Threaded connections have limitations:
Not for high temperatures. Thermal expansion can loosen threaded joints.
Not for severe cyclic service. Vibration can cause threaded joints to loosen.
Limited pressure rating. Threaded joints generally have lower pressure ratings than welded connections.
Wall thickness requirements. Threading removes material, requiring heavier walls (typically SCH 80 or heavier) to maintain adequate strength.
Potential leak paths. The spiral thread path can leak if not properly sealed with thread compound or tape.
Advantages of threaded ends
Simple, rapid assembly
No welding required
Easily disassembled for maintenance or modification
Minimal equipment needed for installation
Widely understood by construction trades
Disadvantages
Limited to smaller sizes and lower pressures
Material removed by threading weakens the pipe
Potential leak paths require careful sealing
Not suitable for high temperatures or severe service
Thread damage during handling can render pipe unusable
Thread protection
Threaded ends require protection during shipping and handling. Plastic thread protectors—caps for external threads, plugs for internal threads—prevent damage that would prevent proper make-up.
At Tianjin Xiangliyuan Steel, we apply thread protectors to all threaded pipe and ensure threads meet applicable standards before shipment. Contact infosteel@xlygt.com for threaded pipe requirements.
Special End Finishes
Beyond the three main categories, specialized applications require other end finishes:
Grooved ends. For mechanical couplings like Victaulic, grooves rolled or cut near the pipe end accept coupling keys. Grooved ends combine with plain or beveled ends depending on the system design.
Expanded ends. Some piping systems use pipes with ends expanded to accept plain end pipes of the same diameter, creating a bell-and-spigot joint.
Flanged ends. Large-diameter pipes may have flanges welded or forged integrally with the pipe. Some specifications call for “flanged ends” where the flange face is part of the pipe.
Peened ends. For some boiler applications, tube ends receive a slight expansion (peening) to facilitate rolling into tube sheets.
End preparation for special welding processes. Automated welding systems may require specific end preparations beyond standard bevels.
Selecting the Right End Finish
How do you choose among plain, beveled, and threaded ends?
Consider these factors:
Connection method. How will pipes connect to each other and to fittings? Butt welding requires bevels. Threaded fittings require threads. Mechanical couplings may work with plain ends.
Pipe size. Threads become impractical above about 4 inches NPS. Bevels work for all sizes. Plain ends suit any size.
Service conditions. High pressure, high temperature, or hazardous fluids generally require welded connections with beveled ends. Non-critical services may accept threaded joints.
Construction environment. Remote locations with limited equipment access may favor threaded joints. Well-equipped shops can handle welding regardless.
Codes and standards. Applicable piping codes may mandate specific end preparations for certain services.
Future maintenance requirements. Systems requiring frequent disassembly favor threaded or mechanical connections.
Cost considerations. Plain ends cost least, beveled ends add moderate cost, threaded ends cost most due to additional processing.
Quality Considerations for End Finishes
However ends are prepared, quality matters. At Tianjin Xiangliyuan Steel, our quality checks include:
Dimensional verification. For bevels, we verify angle, root face, and included angle. For threads, we check taper, pitch, and thread form using appropriate gauges. For plain ends, we confirm squareness and burr-free condition.
Surface inspection. Ends are examined for cracks, laminations, or other defects that could affect joint integrity.
Protection. Appropriate end protectors are applied—plastic caps for beveled ends, thread protectors for threaded ends.
Documentation. End finish specifications are noted on Mill Test Certificates, confirming compliance with order requirements.
For critical applications, third-party inspection may witness end preparation and verification.
Common Questions About End Finishes
Q: Can I specify different ends on the same pipe?
Typically not—a pipe has two ends, and they usually receive the same preparation. However, some specialized applications specify one end prepared differently (for example, one end threaded, one end plain for a swage nipple).
Q: Do beveled ends require protection?
Yes. Beveled ends should have plastic end caps to prevent damage during shipping and handling. Damaged bevels require field rework, defeating the purpose of mill preparation.
Q: What if my field welding procedure requires a different bevel angle?
Standard bevels (30-37.5 degrees) accommodate most welding procedures. If your procedure requires a non-standard angle, specify it clearly in your purchase order. We can produce custom bevels.
Q: How do I specify end finish in my purchase order?
Be explicit. State: “Plain ends, square cut, burrs removed” or “Beveled ends per ASME B16.25” or “Threaded ends, NPT per ASME B1.20.1, with thread protectors.”
Q: Can I field modify mill-prepared ends?
Yes, but doing so defeats the purpose of mill preparation. If significant field modification is expected, consider specifying plain ends.
End Finishes at Tianjin Xiangliyuan Steel
Every pipe leaving our facility has ends prepared to customer specifications. Our capabilities include:
Precision cutting and beveling. Computer-controlled equipment ensures consistent geometry across thousands of pipes.
Threading for all standards. NPT, API, and international thread forms available.
End protection. Appropriate protectors applied to every pipe, preventing damage during transit.
Quality verification. Dimensional inspection ensures every end meets specification requirements.
Flexibility. Standard or custom end preparations to match your project needs.
Whether your project requires plain ends for field customization, beveled ends ready for welding, or threaded ends for mechanical connections, we deliver consistent quality that speeds your installation and ensures reliable joints.
Making the Right Choice
Pipe ends might seem like a minor detail in the grand scope of a project. But like many details, they have outsized impact. The right end finish speeds construction, improves quality, and reduces costs. The wrong choice creates delays, rework, and frustration.
Plain ends offer maximum flexibility but shift preparation to the field. Beveled ends arrive ready for welding, ensuring consistent, code-compliant joints. Threaded ends enable rapid assembly without welding, ideal for smaller pipes and non-critical services.
Understanding these options—and specifying correctly—separates well-managed projects from those plagued by field issues.
Ready to Specify Your End Finishes?
Our technical team understands the nuances of end preparation and can guide you toward the right choice for your application. Whether you need thousands of meters of beveled line pipe for a cross-country pipeline or threaded small-diameter pipe for a local water system, we deliver quality product ready for installation.
Contact us to discuss your requirements:
Email: infosteel@xlygt.com
Website: https://www.xlysteel.com/
Let’s get your project off to the right start—with ends prepared exactly as you need them.
