How to Use Check Pins to Make a Straight Line

Check pins help workers pave straight driveways.

Surveyors, pavers and excavators all rely on straight lines to complete clean and accurate projects. They also know that straight lines don't happen by accident. That's why they use a series of check pins connected by string to help guide their work. Use check pins the next time you work on a paving or excavating project to know that you are working along a straight line.

Things You'll Need

• Rebar
• String

Instructions

1. Drive a piece of steel rebar into the ground where you want the straight line to start. Drive another piece of rebar into the ground where the line should end. The pieces of rebar are your check pins.

2. Orient yourself so that one of the check pins is between you and the other check pin. Stand several feet back from the rebar and crouch down so that the two pieces of rebar are perfectly aligned with each other in your field of vision.

3. Send a helper to a point that is halfway between the two check pins. Have him drive another check pin between the first two pins. From your position, you will see when the piece is perfectly aligned with the first two, and you can help him get the check pin perfectly in line.

4. Tie a string to the first check pin. Keep the string taught and tie it to the center check pin, then the tie it to the last check pin. The string describes a straight line.

Tips & Warnings

• You can continue adding check pins, placing them between the first three pins, depending on the length of your straight line and the needs of your project.