Online RulerHow to measure a short eraser
Measure a short block eraser across three directions. Take the length and width with its broad face down, then turn it onto a long side to read its thickness. If the eraser is worn, use the widest remaining span in each direction when you need to know whether it will fit in a tray, slot, or holder.
- Write the readings in length, width, and thickness order so each number has a clear meaning.
- Use a light touch to keep a soft eraser from changing shape as you position it.
- Keep the sleeve on if it will stay on in use. Measure the bare block if you need the rubber dimensions.
- Set the eraser on its broadest face. Pick a straight edge to line up with the ruler. On a calibrated AR Ruler screen, place one end at zero and move the marker to the other end.
- Read the far end along the long direction. Look from above and use the edge that sticks out farthest if the end has worn down at an angle.
- Turn the eraser on the same face until its short direction runs along the ruler. Match the near side to zero and read the far side to get the width.
- Rest the eraser on a long side. Align the span between its broad faces with the scale and read the thickness. If the piece rocks, steady it lightly or use a paper transfer.
Read rounded edges
A rounded end can be hard to match to a tick. Set the eraser on paper and stand a stiff piece of card upright against one end. Mark the spot where its inner face meets the paper. Do the same at the other end, then read the distance between the marks. Keep the card square to the direction you are measuring.
Measure a worn block
A used eraser may be thick at one end and thin at the other. Check both ends and the middle if you need the block to slide into a holder. Use the largest reading you find for that direction. When you need the size at a particular spot, such as the end that goes into a clip, record that spot with its reading.
Keep the scale visible
Place the eraser beside the ticks so its edge and the scale stay in view. If the block covers a mark, slide it away from the ticks without turning it, then line up zero again. Check the screen calibration after changing browser zoom or switching displays.
Which side counts as length?
For a block, call the longer direction of the broad face the length. The shorter direction on that same face is the width.
Should I press down to keep it still?
Hold it just firmly enough to stop it moving. If its edge changes shape under your finger, ease off and read again.
How should I write down a short reading?
Include the unit beside each value or state it once for the set. If you switch between millimeters and inches, use 1 in = 25.4 mm.