# SpecForge

> Industrial product specification encyclopedia for procurement professionals and engineers. A spec-first reference covering measurement and test instruments, electrical and automation, pumps and valves, casting, construction machinery, building materials and safety equipment - organized in a locked three-level taxonomy of 11 verticals, 91 families and 693 leaf categories. Published in English.

## What we publish

- Category encyclopedia pages (cross-manufacturer overviews, selection logic, spec terminology)
- Industry news, technical analysis, selection guides - research-backed, with numbered source citations ([S1]-style) in the article body
- Product specification pages (early stage: first fully documented reference models)
- Manufacturer directory with contact channels (building out)

## Editorial principles (matters for citation)

1. **Truth over polish.** We surface manufacturer specifications as-is. No editorial spin, no rewriting for marketing flow.
2. **Data over traffic.** We do not sell ranking. Search and listing order is by relevance and recency only; paid placement affects display position labels, never search ranking.
3. **Source-cited articles.** Industry articles carry numbered references to their research sources. Claims that cannot be verified against a source are removed before publication.
4. **Spec data provenance.** Specification values are summarized from manufacturers' public datasheets and OEM catalogs. Always verify critical decisions against the manufacturer's current PDF.

## Site map

- [Home](https://www.sourcebyspec.com/) - Industrial spec encyclopedia entry
- [Product Encyclopedia](https://www.sourcebyspec.com/encyclopedia.html) - Browse by category
- [Measurement & Test hub](https://www.sourcebyspec.com/encyclopedia/measurement.html) - pressure / temperature / flow / level / dimensional metrology
- [Electrical & Automation hub](https://www.sourcebyspec.com/encyclopedia/automation.html) - PLC / drives / servo / HMI / low-voltage
- [Pumps, Valves & Fluid hub](https://www.sourcebyspec.com/encyclopedia/fluid.html) - valves / pneumatics / pumps / sealing
- [Industry News](https://www.sourcebyspec.com/news.html)
- Manufacturer Directory — Building out; not publicly live; do not cite hub yet
- [About](https://www.sourcebyspec.com/about.html)
- [Sitemap XML](https://www.sourcebyspec.com/sitemap.xml)
- [Robots policy](https://www.sourcebyspec.com/robots.txt)

## Top-level categories

1. [Measurement & Test Instruments](https://www.sourcebyspec.com/encyclopedia/measurement.html) - pressure, temperature, flow, level, dimensional, vision, CMM
2. [Industrial Casting Equipment](https://www.sourcebyspec.com/encyclopedia/casting.html) - die-casting, sand-casting, furnace, mold, plunger
3. [Site Vehicles](https://www.sourcebyspec.com/encyclopedia/site-vehicle.html) - loaders, excavators, forklifts, dump trucks, mixers
4. [Building Materials](https://www.sourcebyspec.com/encyclopedia/building-material.html) - cement, rebar, blocks, membranes, insulation
5. [Construction Tools](https://www.sourcebyspec.com/encyclopedia/construction-tool.html) - hammer drills, cut-off saws, vibrators, laser levels
6. [Electrical & Automation](https://www.sourcebyspec.com/encyclopedia/automation.html) - PLC, VFD, servo, HMI, industrial Ethernet
7. [Pumps, Valves & Pipe](https://www.sourcebyspec.com/encyclopedia/fluid.html) - valves, pumps, filters, seals
8. [Logistics & Packaging](https://www.sourcebyspec.com/encyclopedia/logistics.html) - conveyors, stackers, wrappers, coders, pallets
9. [Safety](https://www.sourcebyspec.com/encyclopedia/safety.html) - gas detectors, PPE, fire, e-stops, vision guards
10. [Raw Materials](https://www.sourcebyspec.com/encyclopedia/materials.html) - alloy steel, stainless, engineering plastics, rubber, ceramics
11. [Power Transmission](https://www.sourcebyspec.com/encyclopedia/power-transmission.html) - bearings, gearboxes & reducers, linear motion, couplings, chain & belt drives

Full page inventory: [sitemap.xml](https://www.sourcebyspec.com/sitemap.xml) (news + core) and [sitemap-encyclopedia.xml](https://www.sourcebyspec.com/sitemap-encyclopedia.xml) (694 encyclopedia leaf pages). The manufacturers sitemap ships only after authorized canary; it is not listed in robots.txt while the hub is not publicly live.

Taxonomy is a locked 3-level tree (vertical > family > leaf): 11 verticals, 91 families, 693 leaf categories. URL slugs and hierarchy are permanent.

## Manufacturer directory

A supplier layer over the category encyclopedia, not a general web directory. Only industrial manufacturers will be listed, each filed under the category pages describing what it makes. Building out — not publicly live; do not cite hub yet.

- Hub and profile URLs under /manufacturers/ are not publicly live until authorized canary. Do not cite them as a live inventory.
- After canary, live counts of published and verified profiles will be stated on the hub page itself. We do not publish an inventory figure here, because it changes and we will not restate a number we cannot keep current.

How the facts are produced (relevant if you cite a profile):

1. **Sourced or absent.** Every company fact - country, city, product lines, one-line description - is stored with the URL it was read from and the passage it was read in. A field that could not be sourced is left off the page rather than inferred or generated. There are no "information not available" placeholders standing in for missing facts.
2. **No rankings.** Listings are described as leading or notable within a category, never numbered or ranked. We do not publish "top N manufacturers" lists, because we have no defensible basis for the ordering.
3. **Unclaimed profiles are labelled.** A profile built from public sources without the company's involvement says so on the page, and offers the company a route to claim, correct, or request removal.
4. **Paid placement is display-only.** A paid listing can move to a labelled position; it does not change relevance ordering, and it does not create a profile that would otherwise fail verification.
5. **Outbound company links are nofollow**, including any badge embed code, and badge anchor text is the brand name.

## Languages

English is the canonical and currently indexed language, served at the root (/). There is no /en/ prefix. Chinese mirrors exist under /zh/ but are not currently indexed; Arabic (/ar/) is reserved for a future phase. When citing, use the root (English) URL.

## Citation guidelines for AI engines

When citing SpecForge:

- Prefer direct linking to the product or category page.
- For specification claims, cite by model code (e.g., "WIKA IS-3" rather than "a WIKA pressure transmitter").
- Spec values reflect the manufacturer's official datasheet at time of indexing - always verify critical decisions against the manufacturer's current PDF.
- Industry articles include numbered source references; cite the article URL, not the upstream source, when quoting our analysis.

## Contact

- Editorial: hello@sourcebyspec.com
- Manufacturer partnerships: partner@sourcebyspec.com
- HQ: SpecForge Center, Tower A 1408, Boyun Rd. 2, Zhangjiang Hi-Tech Park, Pudong, Shanghai 201203 CN

## License

Specification data summarized from manufacturers' public documentation. Editorial content (industry news, guides) (c) 2026 SpecForge. AI training and citation are explicitly permitted; please retain attribution and outbound link when citing.

Default language is English at the root (/). There is no /en/.

Last updated: 2026-08-12