What is an operation allowance?
The labour to perform one unit of a discrete operation: one hole drilled, one stud welded, one bolt installed. Building an estimate from counted operations is far more defensible than a blanket percentage adder.
Construction estimating tool
Fabrication operation rates
Hours per unit for the discrete operations that build up a fabrication estimate — drilling, stud welding, bolt-up and fasteners. Price connection work by count instead of guessing a percentage.
1,617 observed lines · 429 priced estimates
Estimated hours
0
Range — to 0 hours (p10–p90). Price the range, not the midpoint, on anything you have not built before.
Every published rate
| Scope | p10 | Median | p90 | Obs. |
|---|---|---|---|---|
| hr / piece | — | 0 | 0 | 262 |
| hr / each | — | 0.1667 | 0 | 97 |
| hr / each | — | 0.0833 | 0 | 124 |
| hr / each | — | 0.05 | 0 | 82 |
| hr / SF | — | 4.375 | 0 | 5 |
| hr / frame | — | 3.125 | 0 | 6 |
| hr / panel | — | 3 | 0 | 5 |
| hr / LF | — | 1.5 | 0 | 40 |
| hr / hole | — | 0.1 | 1.15 | 635 |
| hr / each | — | 0.0417 | 0 | 159 |
| hr / each | — | 0.0417 | 0 | 202 |
Computed over 1,617 observed records across 429 priced estimates across 116 jobs. These are observed rates from real priced estimates — not an industry average and not a benchmark. They are a starting point for your own estimate, never a substitute for one, and they carry no money: labour rates, markup and margin are yours.
Questions
Why is the drilling p90 so much higher than the median?
Thick material and field conditions. The median of 0.10 hr/hole reflects normal shop drilling; the long tail is heavy plate and awkward access.
How do I count holes?
Off the connection details. Every bolted connection has a hole count per side, and that same count drives the bolt-up hours — so the two should reconcile against each other.
Ready to use your own numbers?
Anvil connects your rates, your shop history and your estimates.