Kumar IronUpdated
In this guide
1. Packing date
Every bag carries a packing date, usually month and year, along with the batch details. Cement is best used within about 3 months of packing. Check the date on the actual bags you receive, not just a sample bag. Ask for the freshest stock, and refuse bags whose date is old without good reason.
2. BIS mark and standard
- Look for the BIS (ISI) standard mark with a licence number (CM/L number) on the bag.
- Check the grade and type printed: OPC 43, OPC 53 or PPC, with the matching IS code.
- The brand name, plant and net weight should be printed clearly. Blurred or misspelled printing is a warning.
- Cement sold in unmarked or plain bags, or bags that look re-stitched, should be avoided.
3. Weight
A standard bag is 50 kg net. Short weight is a real problem on sites. Weigh two or three bags at random on a spring or platform scale when the load arrives, and note the readings. Small variations of a few hundred grams can happen, but bags that are clearly short, a kilogram or more, should be reported before the vehicle leaves.
Do the maths on short weight: if every bag is 1 kg short, a 100 bag order is 100 kg short, which is two bags missing.
4. Look, touch and lump check
| Check | Good sign | Warning sign |
|---|---|---|
| Open a bag and look | Uniform grey powder | Hard lumps, patches of different colour |
| Rub between fingers | Smooth and fine | Gritty feel |
| Put a hand into the bag | Feels cool | Feels warm or damp |
| Squeeze a handful | Powder slips through fingers | Forms a hard lump |
| Bag condition | Dry, intact, stitched evenly | Wet patches, torn or patched |
Colour alone proves little. Different brands and plants make slightly different shades of grey. A uniform colour inside one batch is what matters.
The float test and other myths
A common story is that good cement floats on water and bad cement sinks. Fine cement particles can float briefly on the surface because of air and surface tension, and the result says nothing about strength. Do not use it to accept or reject cement.
The tests that actually decide quality are done in a lab: fineness, setting time, soundness and compressive strength at 3, 7 and 28 days. On a big job you can ask the dealer for the manufacturer's test certificate for the batch, and you can have cubes of your own concrete tested at a lab. For an ordinary house, buying fresh BIS-marked cement from a reliable dealer and storing it properly is the practical answer.
5. Recheck after delivery
- Count the bags and compare against the bill.
- Check the packing dates again on the bags that were unloaded last.
- Reject wet or torn bags on the spot and note it on the challan.
- Move bags straight onto pallets in a dry room, as shown in our storage guide.
- Use the oldest batch first, and keep a few bags aside from each lot until the work is done.
If something looks off, call or WhatsApp the store with a photo of the bag and the printed date, and we can help sort it out.
Frequently asked questions
- How do I know if cement is fake?
- Check the BIS mark and licence number, printing quality, net weight and packing date. Buy from a known dealer and keep the bill.
- Does the float test prove cement quality?
- No. Real quality is measured by lab tests for strength, setting time and fineness.
- What should a cement bag weigh?
- 50 kg net. Weigh a few bags at random on delivery.
- How old can cement be when I buy it?
- Ideally within a month or two of packing, and the common working limit is about 3 months.
- Is darker cement stronger?
- No. Colour varies between brands and does not indicate strength.