# Screw Auger API
> Screw-conveyor and grain-auger maths as an API, computed locally and deterministically — the capacity, speed and throughput numbers a farmer, millwright or material-handling engineer sizes an auger with. The capacity endpoint gives the volumetric throughput from the screw geometry: the annular flight volume per turn ((π/4)(diameter² − shaft²) × pitch) × rpm × 60 × the trough loading, so a 9-inch full-pitch screw on a 2.5-inch shaft at 40 rpm and 45 % loading moves about 330 cubic feet — 265 bushels — an hour. The speed endpoint inverts it, the rpm needed for a target capacity, so you don't overspeed a small auger and grind the grain. The bushels endpoint converts a volumetric rate to bushels and tons per hour (1 bushel = 1.2445 ft³, tons = bushels × test weight ÷ 2000), so 330 ft³/hr of 56-lb corn is 265 bushels or 7.4 tons an hour — the number you match to the dryer or the truck. Everything is computed locally and deterministically, so it is instant and private. Ideal for grain-handling and ag-equipment apps, material-handling and conveyor-design tools, farm-build calculators, and engineering aids. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. Estimates — incline and material change real throughput. For belt conveyors use a conveyor API.

## Authentication
All requests require your oanor API key in the `x-oanor-key` header. Get one at https://www.oanor.com/developer/keys.

```bash
curl -H "x-oanor-key: oanor_live_…" "https://api.oanor.com/auger-api/..."
```

## Pricing
- **Free** (Free) — 440 calls/Mo, 2 req/s
- **Starter** ($5/Mo) — 11,600 calls/Mo, 6 req/s
- **Pro** ($17/Mo) — 77,000 calls/Mo, 15 req/s
- **Mega** ($51/Mo) — 254,000 calls/Mo, 36 req/s

## Endpoints

### Auger

#### `GET /v1/bushels` — ft³/hr to bushels and tons

**Parameters:**
- `ft3_hr` (query, required, string) — Volumetric rate in ft³/hr Example: `330`
- `test_weight_lb_bu` (query, optional, string) — Test weight in lb/bushel (default 56) Example: `56`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/auger-api/v1/bushels?ft3_hr=330&test_weight_lb_bu=56"
```

**Response:**
```json
{
    "data": {
        "note": "1 US bushel = 1.2445 ft³, so bushels/hr = ft³/hr ÷ 1.2445, and tons/hr = bushels × test weight ÷ 2000. Test weight is the grain's bulk density — corn ~56 lb/bu, wheat and soybeans ~60. Rate an auger in bushels for grain handling and match it to the dryer or truck so nothing backs up.",
        "inputs": {
            "ft3_hr": 330,
            "test_weight_lb_bu": 56
        },
        "tons_per_hr": 7.42,
        "bushels_per_hr": 265
    },
    "meta": {
        "timestamp": "2026-06-06T23:53:59.082Z",
        "request_id": "788f0b38-994e-4266-9c85-f90e450b5bc4"
    },
    "status": "ok",
    "message": "Bushels",
    "success": true
}
```

#### `GET /v1/capacity` — Volumetric capacity

**Parameters:**
- `diameter_in` (query, required, string) — Screw diameter in inches Example: `9`
- `rpm` (query, required, string) — Screw speed in rpm Example: `40`
- `shaft_diameter_in` (query, optional, string) — Center shaft diameter in inches (default ≈0.28D) Example: `2.5`
- `pitch_in` (query, optional, string) — Flight pitch in inches (default = diameter) Example: `9`
- `loading_pct` (query, optional, string) — Trough loading % (default 45) Example: `45`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/auger-api/v1/capacity?diameter_in=9&rpm=40&shaft_diameter_in=2.5&pitch_in=9&loading_pct=45"
```

**Response:**
```json
{
    "data": {
        "note": "Capacity = the annular flight volume per turn ((π/4)(D² − shaft²) × pitch) × rpm × 60 × the trough loading. Free-flowing grain runs ~45 % loading; sluggish or lumpy material much less. Standard 'full-pitch' screws have pitch equal to diameter — half-pitch handles inclines and meters better. Inclining the auger drops the real capacity fast.",
        "inputs": {
            "rpm": 40,
            "pitch_in": 9,
            "diameter_in": 9,
            "loading_pct": 45,
            "shaft_diameter_in": 2.5
        },
        "capacity_bu_hr": 265,
        "capacity_ft3_hr": 330.2,
        "volume_per_rev_ft3": 0.3058
    },
    "meta": {
        "timestamp": "2026-06-06T23:53:59.172Z",
        "request_id": "82549f22-9b95-4a8f-8959-5a6897d7228c"
    },
    "status": "ok",
    "message": "Capacity",
    "success": true
}
```

#### `GET /v1/speed` — Speed for a target capacity

**Parameters:**
- `diameter_in` (query, required, string) — Screw diameter in inches Example: `9`
- `target_ft3_hr` (query, required, string) — Target capacity in ft³/hr Example: `330`
- `shaft_diameter_in` (query, optional, string) — Center shaft diameter in inches Example: `2.5`
- `pitch_in` (query, optional, string) — Flight pitch in inches (default = diameter) Example: `9`
- `loading_pct` (query, optional, string) — Trough loading % (default 45) Example: `45`

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/auger-api/v1/speed?diameter_in=9&target_ft3_hr=330&shaft_diameter_in=2.5&pitch_in=9&loading_pct=45"
```

**Response:**
```json
{
    "data": {
        "note": "Required speed = target capacity ÷ (volume per turn × 60 × loading). Screws have a max safe speed (smaller diameters spin faster); pushing past it grinds the material and wears the flighting. If the rpm comes out too high, step up a diameter rather than overspeed a small auger.",
        "inputs": {
            "pitch_in": 9,
            "diameter_in": 9,
            "loading_pct": 45,
            "target_ft3_hr": 330,
            "shaft_diameter_in": 2.5
        },
        "required_rpm": 40
    },
    "meta": {
        "timestamp": "2026-06-06T23:53:59.263Z",
        "request_id": "29b7aa6d-60e9-402c-8844-b85c1af933bd"
    },
    "status": "ok",
    "message": "Speed",
    "success": true
}
```

### Meta

#### `GET /v1/meta` — Spec

**Example:**
```bash
curl -H "x-oanor-key: $KEY" \
  "https://api.oanor.com/auger-api/v1/meta"
```

**Response:**
```json
{
    "data": {
        "notes": "US units. Capacity = (π/4)(D²−shaft²)·pitch ÷ 1728 × rpm × 60 × loading; full pitch = diameter; 1 bu = 1.2445 ft³. Estimates — incline, material and CEMA factors change real throughput. For belt conveyors use a conveyor API.",
        "service": "auger-api",
        "endpoints": {
            "GET /v1/meta": "This document.",
            "GET /v1/speed": "Screw speed (rpm) for a target capacity.",
            "GET /v1/bushels": "Convert ft³/hr to bushels and tons per hour.",
            "GET /v1/capacity": "Capacity from diameter, shaft, pitch, rpm and loading."
        },
        "description": "Screw-conveyor / grain-auger maths: volumetric capacity from geometry, the speed for a target capacity, and ft³/bushel/ton conversion."
    },
    "meta": {
        "timestamp": "2026-06-06T23:53:59.364Z",
        "request_id": "c10d3db8-b0ee-47d9-9ac8-3671f9e6eb71"
    },
    "status": "ok",
    "message": "Meta",
    "success": true
}
```


---
Marketplace page: https://www.oanor.com/api/auger-api
OpenAPI spec: https://www.oanor.com/api/auger-api/openapi.json