This pitch diameter calculator takes the figures you already have and applies the relationship behind pitch diameter calculations for you, giving minimum pitch diameter, maximum pitch diameter and basic major diameter from thread pitch, tolerance grade for external thread, tolerance grade for internal thread, tolerance position for external thread, tolerance position for internal thread and td2temp.
What Is the Pitch Diameter Calculator?
The pitch diameter calculator turns thread pitch, tolerance grade for external thread, tolerance grade for internal thread, tolerance position for external thread, tolerance position for internal thread and td2temp into minimum pitch diameter, maximum pitch diameter and basic major diameter, so you can order the right amount of material the first time.
Material estimates are where projects go over budget. Getting the quantities right before the delivery arrives is worth more than any discount on the order.
How to Measure for the Pitch Diameter
Measure everything in the same unit and take the largest dimension you can reasonably use rather than the average. Formwork, ground conditions and cutting waste all push the real figure above the theoretical one.
Where a plan calls for a specific thickness, check it against local building regulations before you order. The calculator reflects the relationship, not the code.
Allowing for Waste and Errors
Order a little more than the calculation suggests. The gap between the theoretical quantity and what actually arrives on site is normally waste, spillage, over-excavation and uneven grading, and all of it comes out of the same budget.
Write the figures down and compare them with what you actually used on site. That is how you build an estimate you can trust for the next job.
A Worked Example
Working through an example, with thread pitch set to 0.2, tolerance grade for external thread set to 0.5, tolerance grade for internal thread set to 0.85, the calculator returns height of fundamental triangle (h) of 0.17321, and upper deviation (es) of -0.5022, and lower deviation (ei) of 0.0172. Substitute your own figures and the same steps produce the same kind of answer.
Frequently Asked Questions
What do I need to work out minimum pitch diameter?
Enter thread pitch, tolerance grade for external thread, tolerance grade for internal thread, tolerance position for external thread, tolerance position for internal thread and td2temp. The calculator then works through the relationship and reports minimum pitch diameter, maximum pitch diameter and basic major diameter.
What does the pitch diameter actually calculate?
It takes thread pitch, tolerance grade for external thread, tolerance grade for internal thread, tolerance position for external thread, tolerance position for internal thread and td2temp and converts them into minimum pitch diameter, maximum pitch diameter and basic major diameter using the standard relationship for this problem. Each step is applied in turn, so every output is traceable back to the numbers you typed in.
How should I enter thread pitch?
Use the value you actually have, in the unit shown next to the field. Enter every value in the same unit system. The calculator assumes the figures you supply are consistent, so it cannot correct a mistake that happens before the calculation starts.
Can I use this for a quick estimate as well as a precise answer?
Yes. The calculator is built for quick checks, so round your inputs to a sensible number of significant figures and the result will be just as useful. If you need more precision, keep the same method and add digits to the inputs rather than adjusting the method itself.
Does anything you type get stored?
No. The whole calculation runs inside your browser, and nothing you enter is uploaded, logged or sent anywhere.