HSW-F2 Series
F2 Class Standard Weight
F2 class precision calibration weights — medium-precision class for standard-tolerance balances and scales.
Manufacturing
Built, installed & supported by HMT
Compliance support
Calibration & Legal Metrology guidance
System ready
Automation, ticketing & ERP integration
01Overview
Sits between F1 (laboratory-grade) and M1 (trade/industrial-grade) in the OIML R111 hierarchy — used where medium-precision calibration is needed but full laboratory-grade F1 isn't required.
02How it works
The middle ground in the OIML hierarchy
F2 sits between F1 (laboratory-grade, the tightest common commercial tolerance) and M1 (trade/industrial-grade, used for weighbridge and platform scale verification) in the OIML R111 hierarchy — a genuinely intermediate tolerance, not just a marketing distinction between the two. It's the class for calibration work that needs more precision than trade verification but doesn't require true laboratory-grade tolerance.
Why 'medium precision' is a real engineering category
A lot of production-floor and quality-control scales — checkweighers, standard-tolerance platform scales used in manufacturing, mid-range laboratory balances — are precise enough that M1 test weights would introduce meaningful calibration error, but not so precise that F1's tighter (and more expensive) tolerance is actually needed to properly calibrate them. F2 is the class engineered specifically for that middle tier of instrument.
Manufacturing tolerance drives material and process choice
Because F2's tolerance band is looser than F1's, it can be achieved without the most exotic low-magnetic-susceptibility alloys and the tightest surface finishing F1 demands — which is part of why F2 weights are less costly than F1 at the same denomination, reflecting a genuinely different (not just relabeled) manufacturing tolerance.
03Manufacturing & build quality
F2 weights are cast or machined from a stable, corrosion-resistant alloy to the nominal denomination, then fine-adjusted to bring the actual mass within OIML R111 F2 tolerance — a process similar in principle to F1 manufacturing but working to a looser tolerance band, which permits somewhat less exotic material and finishing specification. Each weight is checked against a traceable reference standard and marked per OIML R111 F2 requirements before release, documenting both nominal value and certified class.
04Problems it solves
Over-speccing with F1 for standard-tolerance equipment
Calibrating a standard production-floor scale with F1 weights adds cost without a corresponding accuracy benefit, since the instrument's own precision doesn't warrant laboratory-grade calibration weights.
Under-speccing with M1 for precision platform scales
M1's trade-grade tolerance is too loose to properly calibrate a scale with meaningfully finer resolution than a weighbridge — using M1 here understates the calibration error being introduced.
Right-sizing calibration investment across a mixed equipment fleet
A facility with both trade-grade and precision-grade scales benefits from having the correctly matched weight class for each, rather than either over- or under-investing across the board.
Documentation gaps in mid-tier quality control
Production and quality-control scales still need traceable, documented calibration for audit purposes — F2 weights give that documentation at a cost point appropriate to the instrument being calibrated.
05Why it matters
Matching calibration weight class to the actual precision of the instrument being calibrated is a cost-and-accuracy decision that's easy to get wrong in either direction — and F2 exists specifically to close that gap for the large tier of equipment that's more precise than a weighbridge but doesn't need laboratory-grade calibration. Getting this class choice right means every scale in a facility is calibrated to a standard that actually matches what it's capable of, without wasting money over-specifying the coarser instruments or quietly under-serving the more precise ones.
06Salient features
- OIML R111 F2 class tolerance
- Medium-precision calibration use
08Technical file
Need the full technical sheet?
Request drawings, model-specific details and project documentation from the HMT team. A downloadable product file will appear here once approved.
09Complete system
Plan beyond the deck.
A vehicle weighing point can combine the weighbridge with indicator, load cells, traffic management and H-Weigh software for an accountable end-to-end workflow.
09Frequently asked
When should we choose F2 instead of F1 or M1?
F2 fits standard-tolerance production and quality-control scales that need more precision than a trade weighbridge but don't require true laboratory-grade calibration — if you're unsure, compare your scale's own reading resolution against each class's tolerance to find the appropriate match.
What denominations are typically available?
F2 weights are generally available across a similar denomination range to F1, sized to the calibration needs of standard-tolerance balances and platform scales.
What documentation comes with F2 weights for audit purposes?
Certified F2 weights are supplied with documentation confirming traceability to a reference standard and the tolerance achieved against OIML R111 F2 classification — retain this documentation as part of your quality system's calibration records.
How should F2 weights be handled to preserve their tolerance?
Similar care to F1 weights is warranted — clean handling, dry storage, and periodic recertification — though F2's looser tolerance band gives somewhat more margin for minor wear than F1 would tolerate.
How often should F2 weights be recalibrated?
On a schedule matched to usage frequency and your quality system's requirements — typical practice is periodic recertification against a traceable reference standard, similar in cadence to F1 weights.
10Industries this serves
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