These borosilicate glass volumetric flasks have a single graduation mark and a hexagonal hollow glass stopper and are made to DIN ISO 1042. They are used to prepare standard solutions and exact dilutions for titration, spectrophotometry and quality-control work. Each pack contains 2 flasks, available in sizes from 50 ml to 2000 ml.

Key features

• Pack of 2 flasks
• Borosilicate glass
• One graduation mark for exact volume
• Fitted with a hexagonal hollow glass stopper
• Made to DIN ISO 1042
• Six sizes: 50, 100, 250, 500, 1000 and 2000 ml

Technical specifications

Frequently asked questions

What is the accuracy class of these flasks?

ISO 1042 defines Class A, with the tighter tolerance, and Class B, which allows twice the error. The tolerance given for the 250 ml flask, ±0.30 ml, is the Class B limit; Class A would be ±0.15 ml. If you need Class A or a calibration certificate, contact us before ordering.

What does calibrated to contain (In) at 20 °C mean?

The flask holds the stated volume when filled to the mark at 20 °C. It is not meant to deliver that exact volume when poured out, because some liquid stays on the glass.

How do I make up a standard solution?

Dissolve the weighed solid in a small amount of solvent in a beaker, transfer it into the flask with rinsings, then add solvent until the bottom of the meniscus rests on the mark when you look at it at eye level. Insert the stopper and mix by inverting several times.

Can I heat the flask or dry it in an oven?

No. Heating volumetric glassware can distort it and change its volume. Rinse with distilled water and let it air dry, or use a final rinse with a little acetone.

Which size should I choose?

Pick the size closest to the volume of solution you need. Smaller sizes have tighter absolute tolerances, while larger sizes are better for large batches. Sizes available are 50, 100, 250, 500, 1000 and 2000 ml.

Do the stoppers fit every flask?

Each flask has its own hollow hexagonal glass stopper; the 250 ml size has a 14/23 socket. Keep each stopper with its flask, as stoppers are not always interchangeable.

How do I clean it?

Use laboratory detergent and a soft brush, rinse well with tap water and then distilled water. Avoid abrasive powders, which scratch the glass and can affect the volume.

Can I store solutions in the flask?

Use it to make up and mix solutions, then transfer them to a reagent bottle for storage. Leaving alkaline solutions in the flask can attack the glass and make the stopper stick.

How should I read the mark?

Hold the flask upright with the mark at eye level and bring the bottom of the meniscus to the mark. Make sure the solution is at room temperature, about 20 °C.

Can I get a GST invoice and a bulk or institutional quotation?

Yes. Labmart supplies colleges, hospitals, pharma companies and government laboratories across India and issues a GST invoice with every order. For bulk or institutional quantities, send us the size and quantity you need and we will share a quotation.