In this guide 6 sections
The invoice differs because the weight is written down four times by four people. The furnace register, the fettling slip, the inspection sheet and the dispatch note each carry their own figure. Rejections and returns rarely reach the billing clerk. Pricing every invoice from one pattern and weight ledger removes the gap.
Four weights for one casting
A casting is weighed more than once, and each scale answers a different question. The furnace register records the metal poured against a heat number, while the fettling slip records what is left after the runners and risers are cut off.
Inspection then removes pieces for blowholes, shrinkage or a failed dimension. Dispatch weighs what actually goes on the truck. Four numbers describe one job, and the billing clerk usually sees only the last one, or a figure copied from a delivery challan by hand.
Nobody lied. Each person wrote the right number for their own step. The trouble is simple. Nobody owns the sum of the four.
- Heat number and metal poured in the furnace register
- Weight after fettling and shot blasting
- Pieces rejected at inspection, with the reason
- Weight on the dispatch note and the weighbridge slip
Where the gap opens on a Howrah shop floor
A small foundry or machine shop in Howrah often works from a pattern supplied by the customer. The agreed rate may be per kilogram of good castings, per piece or a mix, and the invoice must follow the order. A clerk working from memory guesses the basis. On a busy day the guess is wrong.
Rejections cause the largest slips. The customer returns forty pieces from a lot of two hundred, but the credit note is raised a month later, if at all. Rework adds a second error, because a machined casting that goes back for re-boring is billed once for the job and again for the repair.
Returned scrap goes back into the next melt. One heat then quietly carries weight from an older invoice. Nobody notices.
Why the error shows up only at payment
The customer’s accounts team matches your invoice against their goods receipt note, which carries their own inspection result. If the two differ, the payment is held or cut without a call, and you hear about it weeks later, as a short remittance on the bank statement.
By then the furnace register is full of newer heats and the fettling slips are in a drawer, so reconstructing a month-old lot means walking between three files. The accountant guesses. The customer disagrees. The balance sits as a disputed item.
A shop that sells to a buyer in Kolkata or Durgapur on sixty day terms feels this twice. Once in the delay. Once more in the chasing.
Build a pattern and weight ledger
The fix is one ledger, keyed by customer, pattern number and lot, where each pattern carries its pouring and finished weights, its rate basis and any machining allowance. Every step writes to the same lot line, so the furnace entry, the fettling weight, the rejection count and the dispatch weight sit side by side. One row. One truth.
Price the invoice from that line. Never retype it. Rejections reduce the billable quantity before the bill exists, so the credit note is no longer a month-end surprise. A return creates a linked credit entry against the original lot, so the customer’s later short payment can be matched in a minute.
This is the kind of record that a spreadsheet can hold at small scale and that custom software holds without anyone copying values between tabs.
- Pattern master with pouring and finished weights
- Lot line fed by furnace, fettling, inspection and dispatch
- Rate basis stored per customer and per pattern
- Return and rejection entries linked to the original lot
A first step for this month
Take the last five invoices that were paid short. For each, lay the furnace register line, the dispatch weight and the customer’s receipt note next to the invoice. Mark the first mismatch.
The marks show where the ledger should start. If most gaps sit at rejection, begin by logging every reject with a reason on the day it is found, then price the next invoice from that log.
Pattern and weight ledger sheet
A single printed sheet, ruled by lot. Columns are customer, pattern number, heat number, metal poured, weight after fettling, pieces rejected with reason, dispatch weight, rate basis and invoice number. A second block lists returns with the credit note raised against the original lot.
Open a blank worksheet to printQuestions owners ask
Which weight should a foundry invoice use?
It depends on the order. Many buyers pay on dispatched weight of accepted castings. Others pay per piece. Write the basis on the pattern master so the clerk never decides it from memory.
Why does the customer’s weight differ from ours?
Their scale, moisture, loose sand and a different cut-off for rejects all change the figure. Compare against the weighbridge slip and their inspection sheet, not against the furnace register.
How do we handle returned castings?
Log each return against the original lot with the reason, then raise a linked credit entry. If the piece is reworked and sent again, it should appear as a new dispatch line, not a second full bill.
Can a spreadsheet do this?
For a small shop with a few patterns, yes. It breaks when several people edit it or when lots span many invoices. That is when shared software earns its place.