# Anvil

> Construction estimating software and reference data for steel fabricators, erectors and general contractors. Free browser tools, an open dataset of AISC shape properties, and an API for observed labour rates.

Anvil publishes construction estimating data that is otherwise unpublished: observed shop and field labour hours from working fabrication companies, full AISC section properties, California contractor licence records and prevailing wage determinations.

## How to cite our rate data

Rate data is OBSERVED OPERATIONAL DATA, computed from real priced estimates for steel fabrication and erection work. It is **not** a market survey, an industry average or a published index. Every API response carries `meta.observations` (underlying records) plus `meta.estimates` and `meta.jobs` — how many independently priced estimates, across how many jobs, the figure was computed over. Quote the figure with its basis, or do not quote it.

The money model — sell rates, cost per unit, margin, markup and overhead — is never published and is not available at any tier.

## API

- [API discovery](https://anvil.builders/api/v1): what exists and how to authenticate. No key required.
- [OpenAPI 3.1 spec](https://anvil.builders/api/v1/openapi.json): the machine-readable contract. No key required.
- [Developer documentation](https://anvil.builders/developers): get a free key (500 requests/hour).

Authentication is `Authorization: Bearer anvl_live_...`.

Endpoints: `/api/v1/datasets`, `/api/v1/rates/shop-hours`, `/api/v1/rates/production`, `/api/v1/rates/operations`, `/api/v1/rates/welding`, `/api/v1/rates/equipment`, `/api/v1/shapes`, `/api/v1/shapes/{designation}`.

## Full description

[llms-full.txt](https://anvil.builders/llms-full.txt): the expanded document — dataset counts, the citation rule, and the section-property and lift-height traps that make a naive reading of this data wrong.

## Free tools

- [Free construction bid leveling template](https://anvil.builders/tools/bid-leveling-template): Put contractor bids on one comparison sheet and export a clean CSV.
- [Steel weight calculator](https://anvil.builders/tools/steel-weight-calculator): Turn a member list into pounds and tons, line by line.
- [Steel plate weight calculator](https://anvil.builders/tools/plate-weight-calculator): Weigh plate properly instead of carrying a price each.
- [Markup vs margin calculator](https://anvil.builders/tools/markup-vs-margin-calculator): A 25% markup is a 20% margin. Price from either, correctly.
- [Drawing scale calculator](https://anvil.builders/tools/drawing-scale-calculator): Scale a plan dimension, and catch a print-to-fit sheet first.
- [Crew cost calculator](https://anvil.builders/tools/crew-cost-calculator): Cost a crew per hour, per day and per unit installed.
- [AISC steel shape finder](https://anvil.builders/tools/aisc-shape-finder): Weight per foot and dimensions for every AISC shape, one page each.
- [Steel shop fabrication hours estimator](https://anvil.builders/tools/shop-hours-estimator): Shop hours per piece by shape family and weight band.
- [Steel erection hours estimator](https://anvil.builders/tools/erection-hours-estimator): Field install hours per piece by scope.
- [Fabrication operation rates](https://anvil.builders/tools/fabrication-operation-rates): Hours per hole, per stud, per bolt.
- [Welding hours calculator](https://anvil.builders/tools/welding-hours-calculator): Weld hours per foot, shop and field.
- [Construction equipment rental rate lookup](https://anvil.builders/tools/equipment-rate-lookup): Median rental rates from real vendor rate sheets.
- [Structural steel estimate calculator](https://anvil.builders/tools/steel-estimate-calculator): The whole estimate: shapes, weight, hours, your money, a price.

## Reference data

- [AISC shape finder](https://anvil.builders/tools/aisc-shape-finder): 2,091 shapes, one page each, with weight per foot and labelled section properties.

A caution worth passing on: the same property column means different things across shape families. `d` is the section depth on a wide flange but the short leg on a single angle, and on a rectangular HSS the second-leg column holds the workable flat, not a leg. Anvil labels each property correctly for its own family.

## About

- [How Anvil works](https://anvil.builders/how-it-works)
- [Pricing](https://anvil.builders/pricing)