Tumbler Locks

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As is revealed from the name itself, Tumbler Locks are used for locking of doors, shutters of houses/shops. Tumbler locks are a kind of pad locks. The body of the tumbler lock is pressure die casted from Aluminium or Zinc alloy. The tumbler locks are available in different shapes and sizes, among them the most common are 20, 25, 30, 35 and 46 mm. These locks are opened with the help of a key made from either brass, mild steel or die casted non ferrous metal, To operate the lock, the key is inserted in the key hole provided at the bottom of the

Product Code 343301008
Quality and Standards IS 4230:1967
Production Capacity Qty. : 2.40 Lakh Nos. (per annum)
Value : Rs. 148.8 Lakhs
Uploaded on April 2007

lock, opposite side to shackle. These locks are used to lock windows, Almirah, trunks etc.

The alloy used to manufacture such locks is known as "Mazak" Alloy. Mazak alloy is an alloy having Zinc as the base material. The composition of other elements in Mazak alloy used for this purpose is as follows

Aluminium 4%
Copper 2.7%
Magnesium 0.1 to 0.3%

The alloy having the above composition is hard and strong and can be easily diecasted. Pressure die-casting has been widely used to produce sound and strong castings of accurate dimensions as they need no final machining to size. The surface is smooth and good.

Market Potential

Since Lock is an essential household item, its demand is ever increasing.Tumbler lock being a stout lock is considered to be a good quality lock.

Basis and Presumptions

It is considered that the unit is run 300 days in a year with 16 hours per day. The rates for raw material, labour, machinery etc. have been taken as prevailing at the time of preparation of project scheme. Margin money requirement, terms of loan, interest rates may vary from time to time and institution to institution providing finance, which may be verified. In this project profile, the rate of interest has been considered as 12% per annum.

Implementation Schedule

It is estimated that it may take 4-5 months from conception to commercial production including preparation of project report, finalization of loan from financial institutions, procurement of machinery, erection and commissioning, recruitment of staff and labour, registration and clearance from authorities

Technical Aspects

Process of Manufacture

Tumbler lock consists of the following main components

  • Body
  • Cylinder
  • Levers and its mechanisms
  • Shackle and
  • Tumbler key


Housing of lock mechanism, which contains all the parts except key and shackle is known as body of the tumbler lock. However, one end of the shackle is also fitted in the body. The body of the lock is pressure die casted from Aluminium or Zinc alloy called Mazak Alloy. After pressure die casting, the burrs and sharp edges are removed and polished. Body can also be painted or plated depending upon the requirement.


Cylinder is also pressure die casted part from Aluminium or Zinc Alloy. It is the housing for lever tumbler mechanism. It is fitted inside the body of lock during assembly.

Lever and Lever Mechanism

Levers are mostly press cut from brass or mild steel sheets. These levers along with springs are fitted inside the cylinder which rotates inside the body to keep open or close the lock with the help of key.


It is that part of the lock which passes through the staple loop on the door and is engaged to lock bolt when pushed inside the lock and key is turned lock. Shackle are made from mild steel rods, cut to size, notched and bent to the shape. These are generally nickel plated.


The key is an important member of lock and key arrangement. It is made of brass or mild steel. It is flat, has long bit or blade with V groves made on one or both edges according to the lever mechanism.

All these components are manufactured in various sizes and shapes of the lock. Manufactured components are then assembled and movement of lever cylinder, shackle fixed in position with the help of a pin. The tumbler locks are painted or nickel plated before packing for dispatch.

Production Capacity (per annum)


Qty. in Nos

Price Per Piece

Total (In Rs.)

Tumbler Lock Size 20 and 25 mm 96000 55 5280000
Tumbler Lock Size 30 and 35 mm 120000 65 7800000
Tumbler Lock Size 40 mm 24000 75 1800000
Total 240000   14880000
Motive Power 10 KW.

Pollution Control

No special arrangements are suggested for pollution control. However, proper disposal of electroplating waste must be ensured.

Energy Conservation

No special energy conservation measures are to be taken. However, energy efficient machines have been suggested.

Financial Aspects

Fixed Capital

(i) Land and Building
(i) and 300 sq. mtr. @ Rs. 5000 per sq. mtr including registration 1500000
(ii) Cost of land development, fencing, approach road, inside roads, land scaping, drainage etc. @ Rs. 1000 per sq. mtr. 300000
(iii) Total built-up area 250 sq. mtrs. as follows  
  • Administrative building 50 sq. mtrs. construction cost @ Rs. 7,500 per sq. m
  • Hall cum shed 150 sq. mtrs. construction cost @ Rs.6000 per sq. mtr.
  • Stores, staff canteen etc. 50 sq. mtrs. @ Rs. 6,000 per sq. mtr.
Water System (including Bore Well + over head tank etc) 500000
Total civil cost= cost of land + building 3875000

(ii) Machinery and Equipment


Ind./ Imp.



Total (In Rs.)

Hand operated Hot chamber Pneumatic pressure die casting Machine upto 400 gm.capacity with double Toggle Adjustable all steel made ejector and high speed diesel burner and electricals etc. Ind. 5 120000 600000
Power Press 10MT capacity with 1HP motor and electricals Ind. 2 95000 190000
Air compressors 150 to 200 lbs Sq. inch capacity with 1 HP motor suitable for Pressure die casting machine above at S.No. (1). Ind. 5 20000 100000
Bench Drilling machine 10 mm drill dia capacity with 1/2 HP motor and electricals. Ind. 2 16000 32000
Bench Grinder 200 mm dia wheel and 3/4 HP motor Ind. 1 9000 9000
Lathe 1500 mm bed with 2 HP motor and electricals floor model Ind. 1 125000 125000
Electroplating plant/painting equipments Ind. L.S.   150000
Generator Set(electricity Backup)       300000
Total 1506000
Erection and Commissioning @ 10% of the cost of the machinery 150600
Cost of Dies, Tools and Measuring instruments 150000
Cost of Office equipment and furniture 100000
Total (i) 1906600
(iii) Pre-operative Expenses 50000
Total Fixed Capital ( i+ii+iii ) 5831600

B. Working Capital (per month)

(i) Personnel



Salary (Rs.)

Amount (In Rs.)

Foreman 2 10000 20000
Skilled workers 10 6000 60000
Semi-skilled workers 16 5000 80000
Clerk-cum-Typist 1 8000 8000
Watchman/Peon 2 3000 6000
Total 174000
Employees benefits @ 22% 38280
Total 212280

(ii) Raw Materials





Rate/Unit (Rs.)

Amount (In Rs.)

Mazak Alloy Ind. 3.00 MT 150000 450000
Springs Ind. 200 Kg 50 10000
MS Sheet 24 SWG Ind. 1000 Kg 45 45000
Misc. items such as electroplating salt, paint, oil, diesel etc. Ind. LS     200000
Total 705000

(iii) Utilities


Amount (Rs.)

Power 4000 kWH units @ Rs. 5.5 /unit 22000
Total 22000

(iv) Other Contingent Expenses


(In Rs.)

Postage and Stationery 3000
Transportation 15000
Telephone 3000
Maintenance and Repair 3000
Packing 10000
Insurance 2000
Misc. Expenses 10000
Marketing Expense 20000
Total 66000
(v) Total Recurring Expenditure (per month) (i) + (ii) + (iii) + (iv) 1005280
(vi) Working Capital for 1½ months 1005280 x 1½ 1507920
Say 1507920

C. Total Capital Investment

(i) Fixed Capital 5831600
(ii) Working Capital for 1½ months 1507920
Total 7339520

Financial Analysis

Cost of Production (per year)

Amount (Rs.)

Total recurring cost 12063360
Depreciation on Machinery @ 10% 150600
Depreciation on Building@5% 193750
Depreciation on Dies and Tools @25% 37500
Depreciation on Furnitures @ 20% 20000
Interest on Capital Investment @ 12% 880742
Total 13345952

Turnover (per year)


Qty. Nos. Rate (Rs.)

Total (Rs.)

Tumbler Lock Size 20 and 25 mm 96000 55 5280000
Tumbler Lock Size 30 and 35 mm 120000 65 7800000
Tumbler Lock Size 40 mm 24000 75 1800000
Total     14880000

Profit (per year)


= Rs. 14880000-13345952

  = 1534048

Percentage Profit on Sales (Net Profit Ratio)

  Net Profit (per year) × 100
  = 1534048× 100
  = 10.31

Rate of Return

  Net Profit × 100
  Capital Investment
  = 1534048× 100
  = 20.9

Break-even Point

Fixed Cost

(In Rs.)

Depreciation on Machinery @ 10% 150600
Depreciation on Building@5% 193750
Depreciation on Dies and Tools @25% 37500
Depreciation on Furnitures @ 20% 20000
Interest on Capital Investment @ 12% 880742
Insurance 24000
40% of Salary and Wages 1018944
40% of Other Contingent Expenses (excluding Insurance) 307200
Total 2632736

Profit 1534048
B.E.P Fixed Capital × 100
Fixed Capital + Profit
  = 2632736 × 100
  = 2632736 + 1534048
  = 63.18

Addresses of Machinery and Equipment Suppliers

  • M/s. Basant Industries Corpn.
    Industrial Area 'B',
  • M/s. Hind Engg. Works,
    Opp. D.S. College,
  • M/s. Singhal Engg. Works
    Subhash Road,
  • M/s. Daulat Industries Corporation
    Civil Lines,
  • M/s. Bhag Sons,
    Indl. Area 'B',
  • M/s. Kalsi Machinery Mfg. Pvt. Ltd.
    G. T. Road,
  • M/s. P. K. Engg. Works
    Opp. D.S. College,
  • M/s. Prakash Engg. Works
    Agra Road,
  • M/s. James Engg. Works
    31, Thembur Chetty Street,
  • M/s. Atlas Engg. Works
    G.T. Road,
  • M/s. Perfect Machine Tools Co.
    123-Mount Road,
  • M/s. Hindustan Metal and Engg.Co.
    B–10, End. Carpenter Street,
  • M/s. Komal Industries Corporation
    51-Biggan Street,
  • M/s. Non-Ferrous Metal Corpn.
    174, Sardar Vallabh Bhai Patel
    Road, Mumbai
  • M/s. Bombay Metal Syndicate,
    106-Kila Street,
  • M/s. Essential Machine Tools Pvt. Ltd.
    5-Nyaymurthi, G.N. Vaidya Marg,
    Bank Street, P.O. Box No. 2,
    Behind State Bank, Fort,
    Mumbai - 400001.

For further information please contact

Information Manager
TIMEIS Project
E-mail: timeis@ficci.com