How to Buy Steel Pipe

How to Buy Steel Pipe

Navigating the realm of purchasing pipe can initially seem daunting, but fear not! Once you grasp the fundamentals, the process becomes much smoother. Let's break down the essentials step by step. First and foremost, determining the grade of steel sets the foundation for your pipe selection journey.

Understanding Steel Pipe Basics For many first-time buyers, determining the size of the pipe can be a head-scratcher. Here at Steel Friend, we've devised a handy pipe size chart to serve as your trusty companion in deciphering pipe sizes, available for download below.

It's crucial to distinguish between pipe and tube. While these terms are sometimes used interchangeably, they serve different purposes, come in different shapes, and are measured using distinct techniques. Generally, pipe is utilized for transporting gas, air, or water, whereas tube is primarily employed for structural purposes. Pipe typically boasts a round shape, whereas tube can come in round, square, or rectangular forms.

While tube measurement merits its own discussion, pipe dimensions are determined by length, nominal inner diameter (ID), and pipe "schedule" (wall thickness). It's noteworthy that pipe sizes adhere to an industry standard, ensuring uniform sizing across different grades.

Let's illustrate with an example: a 1-inch pipe would be denoted as follows:

1″ SCH 40 x 20′

Hence, the measured dimensions of this pipe are 1.315″ OD x .133″ WT x 20′. Here, the nominal inner diameter (ID) measures 1.049″. However, it's worth noting that the outer diameter (OD) varies for each ID size; for instance, a 3-1/2″ pipe will have a 4″ diameter, a fact that often confounds pipe novices.

Additional Considerations on Sizes It's imperative to highlight a few other nuances regarding pipe sizes. Once the pipe size surpasses 14 inches, the size specified refers to the outer diameter (OD), rather than the inner diameter as previously described. This convention holds true even for the largest pipes available.

However, there are exceptions to this rule. For instance, the wall thickness remains consistent between Sch 40 and Sch STD (Standard) pipes up to the 12-inch mark. Beyond that, the schedule transitions to Sch 40S (STD) or "True Sch 40."

For example, with 12-inch pipe sizes, the specifications would be as follows:

STD or Sch 40s:

12″ SCH 40s = 12.750″ OD x .375″ WT


Sch 40 (True Schedule 40):

12″ SCH 40 = 12.750″ OD x .405″ WT

This distinction also applies to Sch 80 and Sch 80S pipes.

Determining Your Pipe Needs Moving on, the choice between seamless and welded tubing hinges on the specific requirements of the job at hand. Both types are commonly available in various grades, so it's essential to ascertain your grade needs before reaching out to us. We do not determine the grade for you.

Moreover, customization options for pipe ends, such as beveled ends (BE) or threaded ends, can impact your request. Providing us with this additional information ensures accurate quoting for your specific pipe requirements.

Lastly, the total quantity (footage) of pipe you require is crucial information to include in your quote request.

To recap, here's a handy checklist of what we'll need to provide you with the best possible pipe solution for your project:

  1. Grade of Steel
  2. Pipe Size
  3. Seamless or Welded
  4. Any special pipe end requirements?
  5. Quantity

Rest assured, with these details in hand, we're equipped to cater to your pipe needs seamlessly. Remember, at Steel Friend, we're committed to simplifying your pipe procurement journey.

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