What We Offer

OIML Weights & Weights Sets Our Precision Weights conform to the standard of the Organization International de Metrologie Legale (OIML) International Recommendation R111-1 Edition 2004(E).

Weights are required for used in all the research & development, industries, commerce, laboratories, pharmaceuticals and every standard business, official bodies are required these high precision classified weights and weights sets to fulfill their Quality Standards such as ISO 9001:2008, GLP - Good Laboratory Practice, GMP Good Manufacturing Practice. They are manufactured of Austenitic Stainless Steel with low magnetic permeability and high resistance to corrosion. All surfaces are polished to a perfect, mirror like finish.

Our precision weights are available in Classes E1, E2, F1 and F2. Weights specifications are designed so the specification on all surfaces finish, marking, construction, material density and magnetic properties get more restrictive as the weight tolerances get smaller in order to enable the weight to maintain its tolerances over time. The tolerances for the various classes are established in a manner that enables weights of higher classes to calibrate weights of the next lowest class. Example: Class E2 weights can be used to calibrate class F1 weights.

To get the proper accuracy from your weighing balances provides, you need to perform routine Calibration & Adjustments using the Precision Calibration Weights. Always use the Standard Weights one class ahead than the readability of the weighing balance by that you will get the proper results of your balance. An example that an electronic balance used by a jeweler which gives the result of Accuracy Class M1 then the accuracy of that balance is to be verified by the weights of Accuracy Class F2 weights.

OIML R111 - This international document describes the physical characteristics and metrological requirements of weights that are used for the verification of weighing instruments, for the verification of weights of a lower class of accuracy and with weighing instruments. This document includes a recommendation for seven classes from E1, E2, F1, F2, M1, M2, M3 of weights in tiers of uncertainty. Please see the Table of Tolerances Chart on the tolerances of each weight of a given OIML Class.

Class E1 - Used as primary reference standard for calibrating other reference standard and weights where the stability of the environment and careful handling are assured. Although very stable, one-piece construction Class E1 weights have no method of adjustment and are not suitable for general laboratory use.

Class E2 - Used as reference standard for calibrating other weights and is appropriate for calibrating high precision analytical balances with readability as low as 0.1 mg to 0.01 mg. Class E2 weights can also be used to calibrate Class F1 weights.

Class F1 - Used for calibrating high precision top loading balances with a readability as low as 0.01 g to 0.001 g. Class F1 weights can also be used to calibrate Class F2 weights.

Class F2 - Used for calibrating semi analytical balances and for student use. Class F2 weights can also be used to calibrate weighing instruments for important commercial transaction like gold and precious stones. Class F2 weights can also be used to calibrate Class M1 weights.

Class M1, M2, M3 - Economical weights for general laboratory, industrial, commercial, technical and educational use.


Construction and Shape

As specified in OIML R-111, Weightronics Precision Weights are available in one or two-piece construction.

  • Precision Weights of 500 mg and below are made up of sheet metal and are one-piece construction with one side turned up to make them easy to handle with forceps. Corners and edges are smooth. There are no markings permitted on any sheet metal weights 500 mg and below. The nominal values of weights 500 mg and below are determined by the shape of the weight according to the following table.

    Shape Shape Denomination
    Pentagon 500 mg, 50 mg, 5 mg
    Square 200 mg, 20 mg, 2 mg
    Triangle 100 mg, 10 mg, 1 mg


  • Precision Weights of 500 mg and also available in wire construction as opposed to sheet metal with the same shape configuration as listed in the above table. Our wire weights have one end turned up as well to allow for easy handling with forceps. The nominal values of weights 500 mg and below are determined by the shape of the weight according to the following table.

    Shape Shape Denomination
    5 Segments 500 mg, 50 mg, 5 mg
    2 Segments 200 mg, 20 mg, 2 mg
    1 Segment 100 mg, 10 mg, 1 mg


  • Precision Weights 1 g and above can be either one or two-piece construction. Our OIML Precision Weights 1 g and larger are cylindrical in shape with a tapered neck for easy gripping. They are perfectly flat on top to stack easily on centre. Weights bottoms are slightly recessed to expose the smallest possible area to wear.


  • One-piece construction indicates the weight is manufactured from a single uniform piece of raw material, the weight has no other material added to it, and it has no method of adjustment other than removing material by grinding or polishing. One-piece weights are difficult to manufacture as the only method of final adjustment is removing material by fine grinding or polishing. Class E1 and E2 weights 1 g and larger are cylindrical in shape and are of One-piece construction.

  • Two-piece construction indicates that the weight is constructed of multiple pieces of raw material. In our Precision Weights, weight body is constructed from one piece of material and the lifting knob or head is constructed from a different piece of raw material. Although the head and body may come from different bars of raw material, they are the same grade and type of raw material with the same densities. The knob or head typically screws into the body and one can barely tell the weight is not constructed of one piece of material. There is cavity below the knob thread in the body, which contains adjusting material that is typically the same material from which the weight is made. Class F1 and F2 weights 1 g and larger are cylindrical in shape and are of two-piece construction.



Our weights sets have the same features as the individual weights of their corresponding class. Our weights and weights sets of Accuracy Class E1, E2, F1, F2 are supplied in a Fine Polished Steam Beach Handmade Strong Wooden Cases lined with velvet along with the matching accessories like forceps for lifting the fractional and smaller weights, brushes and Piece of Chamois Leather for cleaning the weights, gloves for not to touch weights with naked hands.

Weights Set Information

Our weights sets are supplied in a 5-2-2-1 series. 5-2-2-1 series means that weights beginning with a "5" and "1" are single in each decade and weights beginning with a "2" are doubled in each decade. For Example: for a set with 5-2-2-1 series from 200 g to 1 g, there is two 200 g, one 100 g, one 50 g, two 20 g, one 10 g, one 5 g, two 2 g and one 1 g.



We also provide you all the accessories you need to properly handle and protect your Precision Weights and Weights Sets. Please contact us for information on new cases, replacement cases or special cases you need to store and protect your Precision Weights and Weights Sets.