How to Calculate Snow Blower Shear Pin Cost in 5 Steps

Step 1: Count the packs the blowers actually need

Start with the blowers kept running, not the packs on sale. Each blower needs its own spare pins, and pins snap without warning — so the default count here is 2 packs, one for the blower in use plus a spare pack in the garage, not one pack that runs out the first time a pin shears on hidden ice. Check every blower before you settle the count, because a second blower kept for a long driveway needs its own packs too, and a neighbour's blower you sometimes borrow is not your spare-pin problem until it is. Write the count down before you look at any price: once a sale price is in front of you, it is easy to buy the packs on offer rather than the packs the blowers need.

Step 2: Find the price per pack

Use the shelf price for the pin size and shear rating your blower actually needs — $12.00 a pack on the defaults. Pins differ in diameter, length and shear rating, and a pin that fits the auger but fails to shear when it should is not a bargain at any price, because the gearbox it was meant to protect costs far more than the pin; likewise a pin that shears too easily leaves you changing pins in the middle of every driveway. Do not use one average price for every blower, and do not use a pin whose rating you have not checked against the manual. If the shop lists a bulk price, divide it by the packs in the bulk lot to get the per-pack price, and check whether that price already includes a discount before you apply another one in step 4.

Step 3: Multiply count by price for the subtotal

The subtotal is the count times the price each: 2 × $12.00 = $24.00. This is the figure before anything is taken off and before any tax is added, and it is the figure most people mistake for the total. It is not the total — it is only the starting point. If your subtotal looks wrong, the count or the price is wrong, because this step is pure multiplication; fix the input, not the arithmetic.

Step 4: Take the discount off the subtotal

Multiply the subtotal by one minus the discount rate: $24.00 × 90% = $21.60 at 10% off. The discount comes off the subtotal, not off the taxed total, and that order matters — it is also why a bigger discount shrinks the tax in the next step. If a voucher applies only to certain packs, apply it only to those packs’ share of the subtotal, not to the whole basket.

Step 5: Add the tax, then check the per-pack figure

Tax is charged on the discounted price: $21.60 × 6% = $1.30, so the total is $21.60 + $1.30 = $22.90. Then divide by the count to check the per-pack figure: $22.90 ÷ 2 = $11.45 a pack. That per-pack figure is the one to compare against other shops and other pins — if it is higher than the shelf price you started with, something went wrong, because a discount should pull the per-pack figure below the shelf price, not above it.

Worked example

2 packs, $12.00 a pack, 10% off, 6% tax. Subtotal: 2 × $12.00 = $24.00. Discounted: $24.00 × 90% = $21.60. Tax: $21.60 × 6% = $1.30. Total: $21.60 + $1.30 = $22.90, which is $11.45 a pack. At 4 packs the same arithmetic gives $48.00 subtotal, $43.20 discounted, $2.59 of tax, $45.79 in all. At no discount the same 2 packs cost $24.00 plus $1.44 of tax, $25.44 in all. The Winter Snow Blower Shear Pin Cost Calculator reproduces every one of these figures from the same inputs.

Three mistakes that break the total

First, taxing the pre-discount price: tax on $24.00 instead of $21.60 adds $0.14 of phantom tax and lands on $23.04 instead of $22.90. Second, counting packs on offer instead of packs the blowers need: buying 4 packs when the blowers need 2 ties up $22.90 that could have stayed in the household budget. Third, using the wrong pin’s size or shear rating: a pin that fails to shear when the auger hits a rock is not a saving if the gearbox is the thing that breaks — price the pin the blower needs, then look for that pin on sale.

Frequently asked questions