Ottoref — Standards MCP Server

io.github.ottonic由 GitHub 帳號 ottonic 發布v0.3.0更新於 Nov 7, 2026

ISO 286 limits and fits, ISO 2768 tolerances, material properties, and process limits.

發布方自己的服務:Standards

已驗證STDIO僅桌面開發者工具資料與分析

概覽

AI 產生的概覽

本機 MCP 伺服器,為助理提供可引用的機械工程參考資料:ISO 286 極限與配合、ISO 2768 公差、材料性質與製程限制。

可以做什麼
  • 列出已實作的標準、材料牌號與製造製程,以及各自的涵蓋範圍
  • 依公稱尺寸查詢 ISO 286 孔或軸的偏差與極限,並列出某公差等級支援的尺寸區間
  • 計算孔軸配合的類型、間隙與過盈,以及單獨的 IT 等級公差值
  • 傳回 ISO 2768-1 對線性、斷裂邊緣與角度尺寸的一般公差,並比對給定偏差是否符合
  • 依牌號查詢典型 SI 材料性質,並將實測特徵與已公布的製程限制進行比對
適用情境
適合回答關於公差尺寸、配合、一般公差標註、材料性質或可製造性限制的問題,也適合需要可追溯至已公布標準表格數值而非近似值的場合。
執行需求
以 stdio 方式作為本機程序執行;README 說明安裝 npm 套件、建置並將 MCP 主機指向編譯後的進入點。未宣告帳號、API 金鑰或環境變數,數值隨原始碼提供。
安裝前請注意
僅提供參考事實:伺服器不判斷設計、配合或零件是否可接受,核准、合規與認證不在範圍內。材料值為典型手冊資料而非設計容許值,製程限制為經驗法則而非某家工廠的實際能力。涵蓋範圍有限,無法核實的數值會被拒絕而非近似給出。

安裝

在 SourceWeft 中

  1. 開啟 儀表板中的 Ottoref — Standards MCP Server,將其新增到工作區。
  2. 為需要使用其工具的對話啟用該服務。

Desktop only,透過 STDIO。 STDIO 服務會啟動本機處理程序,因此需要 SourceWeft 桌面主機。

其他 MCP 客戶端

參照 儲存庫 中的啟動說明。

README

Ottoref — Standards MCP Server

Reference standards for mechanical engineering, as data an assistant can query: ISO 286 limits and fits, ISO 2768 general tolerances, indicative material properties, and published process feasibility limits. Nothing here comes from a CAD file — it is the reference layer that turns a measurement, or a measurement-plus-drawing question, into an answer you can cite.

Every value is taken from the published tables, carries the edition it came from, and is checked against independent fixtures. Anything the server cannot verify, it refuses with a reason rather than approximating — so a number from this server is one you can put your name to.

Tools

ToolReturns
list_standardsWhich standards are implemented, and what within each is covered.
limits_of_sizeUpper and lower deviations and limits for one ISO 286 class at one nominal size, e.g. 36H7.
iso286_applicabilityExact size intervals where one ISO 286 tolerance class is supported, e.g. H7, j5 or N9.
fitFit type, clearance and interference for a hole and shaft pair at one nominal size, e.g. 12 H7/h6.
it_gradeThe standard tolerance value for one IT grade at one size, in micrometres and millimetres (IT01, IT0, IT1–IT18).
general_toleranceThe ISO 2768-1 general tolerance for a class: linear, broken-edge, or angular.
general_tolerance_compliesWhether a stated deviation complies with a general-tolerance note.
material_propertiesTypical SI properties for one material designation.
material_coverageWhich material grades and families are covered.
process_limitsPublished geometric feasibility limits for a process.
process_feasibilityA check of a stated value against those process limits.
process_listWhich processes are covered.

What it covers

ISO 286-1:2010, with Cor 1:2013 applied provides standard tolerance grades IT01, IT0 and IT1 to IT18 for nominal sizes up to 500 mm. Shaft limits cover c–h, k, m, n, p, r–v, x–z, and za–zc where Table 4/5 publishes a cell, using its exact size intervals and grade rules. Verified hole classes C, D, E, F, G, H, JS, K, M, N, P, R, S, T, U, V, X, Y, Z, ZA, ZB, ZC use the Table 2/3 ∆ corrections and the M6 exception, and grade-specific shaft j5–j7 (and j8 up to 3 mm) and hole J6–J8 use their own table values. iso286_applicability reports the exact supported size intervals for a class; gaps are stated, never interpolated.

ISO 2768-1:1989 provides general tolerances for linear dimensions (classes f, m, c, v), broken edges (classes f and c), and angular dimensions (classes f, c, v), plus a compliance check for a stated deviation.

Materials are indicative typical values for common metals and plastics, from an Apache-2.0 reference, tagged basis: typical. Process limits are published rules of thumb for cnc-machining, sheet-metal, injection-molding, and additive-sls.

Out of scope, and refused rather than guessed: nominal sizes above 500 mm and the inch counterparts (ANSI B4.2); IT01–IT2 K/M/N/P–ZC combinations and sparse Table 2/3 cells with no published ∆ value; design allowables, fatigue, and high-temperature data; and a specific shop's capability, achievable tolerance, cost, or lead time.

How the values are produced

The values are the published tables, which are normative. The earlier editions also define the tolerance factor i = 0.45·∛D + 0.001·D and give the grades as multiples of it; that arithmetic reproduces the table at 18 mm and above but diverges at the smallest size step, where the published IT18 is 1400 µm against 2500i = 1355 µm. toleranceFactor() is kept as a documented cross-check, and the tests assert both the table and the divergence.

What it does not do

It reports what a standard specifies. It does not decide whether a design is acceptable, whether a fit suits a joint, or whether a part can be made — those are engineering judgements and they stay with you. Approval, compliance, and certification are out of scope.

Install and run

sh
npm installnpm run buildnode dist/src/index.js        # serves MCP over stdio

Point an MCP host at dist/src/index.js. The server serves both protocol eras: the 2025-11-25 handshake that stock MCP hosts negotiate, and the 2026-07-28 envelope through server/discover.

Development

sh
just check          # fmt-check, lint, typecheck, testjust buildjust test

just check is keyless and needs no data files: the values are in the source.

Packaging

npm pack builds first and includes the compiled server and this README; tests and source maps are excluded. Install the tarball to check the standards-mcp executable with a compatible MCP client.

License

MIT. Third-party notices: THIRD_PARTY_NOTICES.md.

來源:README.md,提交 f9da2c7

工具

12

list_standards

List Standards Coverage

List the standards this server implements, and what within each one is not covered. Call this first when a question mentions a standard, so you know whether the value you need is available before you promise an answer. Coverage is partial by design: unimplemented values are refused with a stated reason rather than approximated. Use iso286_applicability for exact size intervals of an ISO 286 class.

無需輸入參數。

limits_of_size

Limits of Size for a Tolerance Class

Return the upper and lower deviations, and the resulting limits, for one tolerance class at one nominal size, such as 36H7 or 36g6. Uppercase is a hole, lowercase a shaft. Values are millimetres and are deviations from the nominal size. Use this to interpret a toleranced dimension; whether the resulting limits suit a joint is an engineering decision.

輸入參數nominal必填designation必填

iso286_applicability

Check ISO 286 Class Applicability

List the exact nominal-size intervals where one ISO 286 tolerance class is supported, such as H7, j5 or N9. Use this before relying on a class across a size range; omitted intervals are not inferred.

輸入參數designation必填

fit

Fit Between a Hole and a Shaft

Return the resulting fit between one hole class and one shaft class at the same nominal size, such as 12 H7/h6: the type (clearance, transition or interference), the minimum and maximum clearance, and the maximum interference. Values are millimetres. A negative minimum clearance means the fit can interfere. This reports the geometry of the fit, not whether it is the right choice for a joint, which depends on function and is the caller's decision.

輸入參數hole必填shaft必填nominal必填

it_grade

Standard Tolerance Grade Value

Return the standard tolerance value for one IT grade at one nominal size, in micrometres and millimetres, with the size step it came from. Use this when a drawing or a calculation needs the tolerance width itself, rather than the limits of a specific class.

輸入參數grade必填nominal必填

general_tolerance

ISO 2768-1 General Tolerance

Return the deviation that a general-tolerance note such as ISO 2768-m implies for one dimension, so an unmarked dimension can be checked. The tables differ by what they cover: linear dimensions, broken edges (external radii and chamfer heights), and angular dimensions, which are keyed by the shorter side of the angle rather than the nominal size. A general tolerance applies only where the drawing gives no individual tolerance, so check for one first.

輸入參數kindnominal必填tolerance_class必填

general_tolerance_complies

Check a Deviation Against an ISO 2768-1 Note

Compare a stated deviation numerically against the ISO 2768-1 general-tolerance value for one dimension. This is only a numeric comparison: first establish that the dimension has no individual tolerance indication, because the general tolerance applies only to unmarked dimensions. The result does not establish process capability.

輸入參數kindnominal必填tolerance_class必填stated_deviation必填

material_properties

Material Properties (Typical Values)

Look up indicative material properties for a common metal or plastic by designation, such as 6061-T6, 304 or Ti-6Al-4V. Returns density, yield and ultimate strength, Young's modulus, Poisson's ratio, elongation, thermal expansion and maximum service temperature, all in SI. These are TYPICAL handbook values, not design allowables: every value is tagged basis: typical. Use them to compare materials, estimate mass, or supply an indicative modulus to an analysis; obtain an allowable from a qualified source before relying on a strength margin. An unmatched designation means this reference does not hold it, not that the material does not exist.

輸入參數material必填property

material_coverage

What Material Data Is Held

List what the material reference holds and what it does not. Call this when a material was not found, or before promising a property, so a gap is visible rather than assumed. The reference is limited to typical values for common metals and plastics: it holds no design allowables, no fatigue data and no high-temperature data.

無需輸入參數。

process_limits

Manufacturing Process Limits

Describe what a manufacturing process can hold: minimum wall thickness, minimum hole-to-edge and hole-to-bend distances, minimum internal corner radius, bend radius, draft angle, pocket depth-to-width ratio. Call process_feasibility to test one measured feature against these. These are published rules of thumb for geometric feasibility, not a specific shop's capability, and they say nothing about cost or lead time.

輸入參數process必填

process_feasibility

Check a Feature Against Process Limits

Compare one measured feature against a manufacturing process's limits and report whether it is within, marginal, or beyond them. Some limits are expressed as a ratio of material thickness rather than an absolute size — a 1 mm hole is fine in thin sheet and difficult in thick plate — so supply the thickness when the limit needs it. A result inside the limits is not a promise that a shop can make the part, or an estimate of what it costs. Pair this with a measured wall or hole size from a CAD server to answer whether a part suits a process.

輸入參數feature必填process必填measured必填thickness

process_list

List Manufacturing Processes

List the manufacturing processes this server has limits for, and which features each one covers. Call this first when a question names a process, so an unsupported process is visible before a check fails.

無需輸入參數。

版本歷史

1
  1. v0.3.0最新Oct 31, 2026

評分

已滿足適用檢查項的 90%

該評分衡量此收錄條目的完整程度,依據註冊中心條目、端點與公開來源計算得出。它不是對伺服器本身的評價,也不表示伺服器安全或目前可用:可連通性是帶日期的檢查結果,評分也不包含安裝量或使用者評價。

  • 近 30 天內可連通25 分
  • 已宣告認證方式10 分

    請在註冊中心條目中宣告憑證請求標頭,或保持端點能夠回應探測,以便判定其認證方式。

  • 已列出工具必需15 分
  • 描述必需15 分
  • 圖示10 分
  • 文件15 分
  • 授權條款10 分

其他 Standards 整合