What is the size of test tube?
Users often ask what is the size of a test tube and if there are any kinds of them.
All the test tubes are designed according to the user's suggestions. Now in the market, the test tubes sizes are calculated by two ways:
1.by outer diameter and full length(the most common used test tubes ,no calibration;)2.by volume. (with calibration).
There are 3 kinds of test tubes often used and people calculate them only by outer diameter and full length.
Round Bottom Test Tube
The most common used glass Test Tubes, the precipitate can be observed clearly.
Flat Bottom Test Tube
Such design makes the test tube can be put on the flat desk top and will not fall down, so such test tubes are always not very long to make the test tubes keep stability of the center of gravity.
Test Tube With Rim
Such design makes the test tube will not slip from the test tube clamps.
We have the following common sizes for reference:
If you want more details, you can click here to visit our test tubes pages:
>>Round bottom test tubes
>>Flat bottom test tubes
>>Test tubes with rim
As the machines which made them can easily adjust the diameter and length, customers always ask to make their customized sizes. According to test needs, people have developed some plastic test tubes, the common sizes are:3.5ml(12*60mm);5ml(12*72mm);7ml(12*100mm);5ml(13*75mm);5ml(13*78mm);7ml(13*100mm);10ml(13*145mm);10ml(14.5*100mm);10ml(15*100mm);16ml(15*150mm); 12ml(16*95mm);13ml(16*100ml);20ml(16*150mm);10ml(17*105mm);17ml(18*105mm);30ml(20*150mm);40ml(25*150mm).
Quite different from the test tubes calculated by outer diameter and full length, the test tubes calculated by volume are always specified length and outer diameter, because the manufacturer has to test the calibration again and again and take notes before making them. The general sizes are usually:5ml/10ml/15ml/20ml/25/50ml/100ml/150ml. If the user asked to make his customized sizes, the manufacturer will not easily agree because to make the scale accurate, the manufacturer will have to do a lot of tests.
Which test tube are you going to order, by certain OD(outer diameter) and length or you just want the graduated test tubes?