Neck Finish Standards on Indian Glass Bottles: IS 7511 and IS 1662

India has its own published geometry for glass bottle necks: IS 7511, Dimensions for Neck Finishes, issued by the Bureau of Indian Standards under the Glassware sectional committee CHD 10 in eight parts. Part 4 matters for aluminium roll-on closures: it specifies roll-on threads pilferproof finishes in four depths, across nominal sizes from 22 mm to 70 mm, with a tolerance band on every dimension. Product standards call it up, so IS 1662 for glass liquor bottles and IS 11984 for free flowing liquids both point back to it.

Key takeaways

• IS 7511 (Part 4) covers roll-on threads pilferproof, abbreviated ROSPP, in standard, shallow, deep and extra deep types.
• On the 28 mm standard finish the thread measures 26.77 to 27.41 mm across and the underside of the locking ring sits 15.17 to 15.67 mm below the top, on a 3.63 mm pitch.
• IS 1662 sets the pilfer-proof finish diameter for glass liquor bottles by capacity, and points to Part 4 for dimensions.
• IS 11984 requires glass bottles for free flowing liquids to carry a 28 mm or 31.5 mm ROPP standard neck finish conforming to Part 4.
• Pharmaceutical glass containers are covered by IS 1108, with the finish still taken from IS 7511.
• There is no published Indian Standard for the aluminium closure itself. The standards define the bottle; the cap is matched to it.

The Indian standards for glass finishes, and the closure each takes

Two kinds of standard are involved. IS 7511 gives the geometry of the neck. Product standards for particular bottles say which of those finishes a bottle must carry.

Parts 3 and 4 are the roll-on pair. Part 3 is for a roll-on closure with no tamper band; Part 4 also carries the locking ring a pilfer band tucks under. Anything sold in India as a pilfer-proof cap runs on a Part 4 finish or its equivalent. IS 7511 began as a summary sheet on glass container neck finishes and was retitled once it was clear the document was mainly geometry.

What IS 7511 (Part 4) actually specifies

Part 4 defines four types, and the type changes the depth of the neck rather than its diameter. Table 1 gives maximum and minimum values for each dimension letter, with helix angle, cutter diameter and pitch. The letters, as drawn in the standard, are: T, the diameter across the thread; E, the diameter at the root of the thread; H, the height from the top of the finish down the threaded section; F, the depth from the top to the underside of the locking ring; L, the diameter of the locking ring; and N, the maximum neck diameter below the ring.

The shallow 46 mm H maximum is shown as corrected by Amendment No. 1 of October 1987, which substitutes 8.71 for the 9.71 printed in the original table, so ask for the amended copy. Read the table down the F column and the depth classes show plainly: 15.17 to 15.67 mm on the standard 28, 21.14 to 21.64 mm on the deep 31.5, and 31.70 to 32.20 mm on the extra deep 30. The same diameter can carry a short neck or a tall one, and the closure skirt has to follow; long skirt vs short skirt ROPP caps works through what that means for the cap.

Three more clauses are worth quoting to a glass supplier. The sealing surface must remain flat to a minimum of 0,9 mm as well as meeting the tabulated dimensions, and be as regular and smooth as possible. Essential dimensions may be checked by an appropriate method of measurement or with suitable gauges, and the standard notes that the maximum and minimum of T, E, L, F and N may be determined with gauges. Any alternative finish involving a transfer ring should be confirmed with the glass manufacturer.

Two readings from the table catch buyers out. The “30 mm” extra deep finish measures only 27.99 to 28.63 mm across its thread, so a spirits bottle can caliper like a 28; the depth to the ring is what separates them, and how to measure bottle cap size turns these bands into a lookup. And the 38 mm shallow finish here is cut at a 3.17 mm pitch, while CETIE’s 38 mm standard ROPP glass finish, GME 401, runs at 7 turns per inch, which is 3.63 mm. The two are not the same 38 mm finish. How closures are checked against these tolerance bands on arrival is covered in cap dimension tolerances and QC sampling, and the ROPP cap size chart lists what is in circulation.

The liquor bottle case: IS 1662

IS 1662, Specification for Glass Liquor Bottles, is the clearest case of an Indian product standard reaching into finish geometry. It rationalised liquor bottles to five capacities and fixed the pilfer-proof finish diameter for each.

Two agreed departures follow. The 250 ml and 180 ml bottles may take a 28,0 mm finish by agreement, and for Indian made foreign liquor the 750 ml bottle may take a 31,5 mm standard or deep finish, or a 30,0 mm extra deep finish. Read that against the Part 4 table and it lines up: 31.5 mm exists in both standard and deep, 30 mm only as extra deep. The tall skirts on Indian spirits are that clause in physical form; liquor bottle caps in India covers the segment, and the European deep wine and spirits finishes are set out in BVS neck finishes. IS 1662 also grades the glass, requiring Type 4 under the alkalinity clause when graded by IS 2303, with a thermal shock test to IS 6506.

How Indian designations map to the international ones

Indian glass plants quote IS numbers, bottlers often receive drawings quoting European ones, and closure suppliers work to whichever arrives. The systems are parallel, not identical, so this is for orientation only.

That mapping is not a guess. IS 7511 (Part 4) states in its explanatory note that assistance was derived from ISO 8162-1985, ISO 8163-1985, ISO/DP 9100, BS 1918 Part 1 of 1978 and BS 1918 Part 2 of 1981. The European 28 mm finishes that aluminium closures run on, with their data sheet numbers, are listed in glass bottle neck finishes for ROPP caps.

What no Indian standard covers is the closure. There is no published IS specification for an aluminium roll-on cap the way there is for the bottle, which is why buyers work from the bottle drawing and a sample. Neck finish codes and cap sizes explains the codes, and 28mm ROPP caps covers the dominant Indian diameter. R Vision’s Aqua Cap and Bev Cap are 28/15 mm aluminium ROPP closures supplied against the MCA I/II/III, MCA 7.5 R, MCA 7.5 RF and PET BPF finishes; every other size on this page is industry reference.

Frequently asked questions

Which Indian Standard covers glass bottle neck finishes?

IS 7511, Dimensions for Neck Finishes, published by the Bureau of Indian Standards under the Glassware sectional committee. It runs to eight parts, one per finish family: shallow continuous thread, shallow continuous thread for deep screw caps, roll-on non-pilferproof, roll-on pilferproof, vial goldie seal, dual neck, crown and vacuum lug.

What does IS 7511 Part 4 specify?

Dimensions for roll-on threads pilferproof finishes, abbreviated ROSPP, in four types: standard, shallow, deep and extra deep. Its table covers nominal sizes 22, 25, 28, 30, 31.5, 38, 46, 53 and 70 mm with maximum and minimum values for thread diameter, root diameter, depth to the locking ring and ring diameter, plus helix angle, cutter diameter and pitch, and requires the sealing surface to stay flat to a minimum of 0,9 mm.

What are the dimensions of a 28 mm ROPP neck finish under IS 7511?

On the Part 4 standard finish, the thread diameter is 26.77 to 27.41 mm, the root diameter 24.53 to 25.17 mm, the depth from the top to the underside of the locking ring 15.17 to 15.67 mm and the ring diameter 27.40 to 28.04 mm, on a 3.63 mm pitch. A 28 mm finish is listed only as a standard finish in Part 4.

What neck finish do Indian liquor bottles use?

IS 1662 specifies a pilfer-proof finish of 28,0 mm nominal diameter for 750 ml, 500 ml and 375 ml bottles, and 25,0 mm for 250 ml and 180 ml. For Indian made foreign liquor the 750 ml bottle may instead take a 31,5 mm standard or deep finish, or a 30,0 mm extra deep finish.

Is there an Indian Standard for the aluminium cap itself?

Not in the way there is for the bottle. Indian standards define the container and its finish geometry, and the roll-on closure is matched to it. Because the cap’s thread is formed during capping, the finish drawing is the controlling document.

How do IS finishes relate to MCA codes?

They are parallel systems covering the same job. IS 7511 Part 4 corresponds to the ISO pilferproof finish series, and the 28 mm roll-on finishes correspond to the European MCA finishes CETIE publishes as GME sheets. Similar geometry is not interchangeable geometry: the Indian 38 mm shallow finish and CETIE’s 38 mm standard ROPP finish are on different pitches.

Sources

• BIS, IS 7511 (Part 1): 1992, Dimensions for Neck Finishes, for the series title, committee and parts.
• BIS, IS 7511 (Part 4): 1986, Roll-on Threads Pilferproof, for finish types, Table 1 dimensions and pitches, the sealing surface and gauging clauses, Amendment No. 1 and documents consulted.
• BIS, IS 1662: 1974, Glass Liquor Bottles, for finish diameters by capacity and the IMFL clause.
• BIS, IS 11984: 1986, Glass Bottles for Free Flowing Liquids, for the ROPP finish requirement.
• BIS, IS 1108: 1975, Pharmaceutical Glass Containers.
• ISO, ISO 9056:1990, series of pilferproof finish.
• CETIE, Finish data sheets (GME), for the MCA sheets and GME 401.

R Vision Pvt. Ltd manufactures 28/15 mm aluminium ROPP closures from Sinnar, Nashik. Send the drawing your bottle was made to through contact us.