SPARE IDENTIFICATION / GRADING SYSTEM
Keep the decimal.
Keep the system.
One digit in common does not make two bolt classifications interchangeable.
Introduction
A distributor requests a replacement bolt and receives a quotation labelled “Grade 8.” The original reference mentions “8.8.” Someone removes the decimal in the purchasing sheet and accepts the quote because both descriptions appear to mean a strong bolt. The order now contains an unresolved specification change disguised as a spelling correction.
The missing context is the grading system. Bolt Depot separates US bolts from metric bolts in its public strength chart. Grade 8 appears in the US section, while Class 8.8 appears in the metric section. Those labels should not be merged into one searchable stock code.
This guide concerns the quotation and approval record. It does not identify the bolts used in any WEIMI machine, calculate a joint load or authorize a substitution. The products below are real public listings selected for procurement discussion; their fastener specifications remain configuration-specific questions.
Quick Answer
US Grade 8 and metric Class 8.8 are separate classifications. Do not treat one as an abbreviated spelling of the other. Preserve the exact designation, grading system and complete part reference in the spare-parts request.
Bolt Depot shows six radial lines for Grade 8 head marking and a separate Class 8.8 head-marking example. Its US table expresses size ranges in inches and mechanical properties in psi; its metric table uses millimetres and MPa. Reading the shared digit without those headings loses important context.
Ask the equipment supplier to confirm the approved replacement for the identified assembly. A strength-chart entry alone does not establish thread compatibility, dimensional fit, finish compatibility or suitability for a particular joint. Do not install an uncertain substitute as a way to discover whether the quotation was correct.
Comparison Table
| Reference | What the public chart shows | Purchasing consequence |
|---|---|---|
| US Grade 8 | Separate entry under US Bolts; six radial lines shown | Retain the US grading reference and the complete inch-series part specification |
| Metric Class 8.8 | Separate entry under Metric Bolts; Class 8.8 marking example | Retain the metric property class and complete metric part specification |
| A quote saying only “8” | The intended designation is ambiguous | Request clarification rather than completing the label yourself |
| A bolt that appears to fit | Appearance or fit does not establish the approved mechanical specification | Match the approved part record and supplier confirmation |
| A proposed stronger alternative | A chart comparison is not assembly approval | Request a documented substitution decision for the actual joint |
These entries explain how to read a reference table. They are not recommendations for which bolt to use in a vending cabinet.
Who Should Buy This
This review is useful for overseas distributors building a spare inventory, maintenance coordinators ordering from a local fastener supplier and purchasing teams translating equipment part lists. The risk increases when one organisation normally buys US inch-series hardware while another normally works with metric descriptions.
It also helps buyers comparing machines whose service documentation comes from several sources. A supplier may use an internal part code while a repair contractor asks for a commercial bolt designation. Keep both references linked instead of replacing one with a guessed equivalent.
If the equipment supplier already provides a complete approved spare under an exact part number, preserve that identity. A generic chart should not become a reason to discard more specific assembly documentation.
How We Evaluate Smart Vending Machines
We review three publicly listed WEIMI retail formats and identify questions a buyer can ask about spare identification. This is a procurement shortlist based on public descriptions, not independent testing of machines, bolts, service life or joint strength. No fastener grade is verified for any listed model.
The classification background comes from Bolt Depot’s Bolt Grade Markings and Strength Chart, read directly for this guide. The evidence supports the distinction between its US and metric sections, their marking examples and their stated units.
The chart is a general reference from a fastener seller. It is not the drawing, bill of materials or replacement approval for your machine. We therefore use it to expose an ambiguous description, then direct the buyer back to the responsible equipment supplier for the actual selection.
Key Buying Factors
Copy the whole designation. Keep “Grade 8” and “Class 8.8” exactly as supplied until the responsible provider clarifies the reference. Avoid spreadsheet cleaning rules that strip punctuation from engineering descriptions. Record a supplier correction explicitly instead of silently normalising it.
Identify the assembly first. Include the machine configuration, assembly reference and approved spare code. A cabinet can contain different fastening tasks; a description from one location should not be applied to another solely because the heads look similar.
Retain dimensions independently. The grading designation does not replace diameter, thread details, length or head form. Keep those fields separate in the order. Ask the supplier to complete missing values rather than using a grade label to infer the rest.
Keep material and finish visible. A strength entry does not describe every purchasing requirement. Request the specified material and surface treatment where applicable, together with the approved part identity. This guide makes no claim that a particular finish or alloy suits a WEIMI assembly.
Read units with properties. Bolt Depot’s US and metric tables use different units. A copied strength number without its unit and size range can mislead the review. Do not compare naked spreadsheet values or convert them into a cabinet load rating.
Use markings as evidence, not complete approval. Ask for clear identification and supporting part information. A marking photograph can help resolve a description, but it does not show every dimension, source record or assembly requirement. An unreadable marking is an unresolved question, not permission to assume a class.
Separate purchasing from installation. Get the correct approved part, then follow the equipment supplier’s applicable service instructions. This article provides no tightening torque, lubrication instruction, reuse rule or repair procedure.
Best Smart Vending Machines
The following three products represent different retail workflows. Their inclusion does not imply they share hardware or that one has stronger fasteners. Each requires its own configuration-specific spare record.
1. WEIMI WM22 touchscreen snacks and drinks machine
The WM22 public listing describes a touchscreen snacks-and-drinks format with promotional display and remote-operation features. It is a starting point for buyers seeking that dispensing workflow.
Ask how the supplier identifies replacement parts for the quoted cabinet and fitted options. Keep an internal spare code linked to the supplier’s approved description. Do not infer a bolt grade from the presence of a touchscreen or from cabinet photographs.
2. WEIMI single-door AI retail fridge
The single-door AI fridge listing presents an open, select and close workflow for packaged products, with camera recognition and cloud management. The product description is not evidence of a juice-squeezing process or guaranteed recognition performance.
For this format, request the relevant spare references by assembly and configuration. Camera-related sales features do not identify the mechanical hardware around a door, shelf or other part. Leave every unverified fastening detail open for the supplier’s response.
3. WEIMI dual-cabinet vending machine
The dual-cabinet public listing shows main and secondary display areas, spiral lanes and a menu/payment area. It supports discussion of the retail layout without proving shared power, controller, network or fastening architecture.
Request a part reference that identifies the intended cabinet and assembly. Similar-looking hardware across two cabinets should not be combined in one spare bin until the supplier confirms the common approved part.
Feature Comparison
| Public-listing format | Reason to shortlist | Spare evidence to request |
|---|---|---|
| WM22 touchscreen | Snacks and drinks with a touchscreen purchasing path | Approved replacement identity for the quoted configuration and options |
| Single-door AI fridge | Packaged-product selection through an open/select/close workflow | Assembly-specific part references; no grade inferred from AI features |
| Dual-cabinet machine | Retail layout with main and secondary display areas and spiral lanes | Cabinet and assembly mapping before grouping spare stock |
No listing establishes US Grade 8, metric Class 8.8, a universal torque or a common bolt set. Procurement suitability depends on your retail requirements and the evidence supplied with the actual quotation.
Cost & ROI Analysis
An ambiguous spare description creates a coordination task before it creates a measurable saving. Estimate the administrative work separately from hardware prices, delivery costs and any service consequences. Do not use a strength-chart number as an ROI input.
Hypothetical planning example: assume a purchasing coordinator spends 24 minutes clarifying the original part reference and the supplier’s grade description. At an assumed internal labour rate of $65 per hour, the review allowance is 24 ÷ 60 × $65 = $26. This is an illustrative labour calculation, not a WEIMI quote, observed case or promised saving.
That allowance excludes the bolt price, freight, technician work and any delay. Obtain actual figures if they matter to the decision. A local substitute with a lower unit price is not automatically an economical option when its approval remains unresolved.
For recurring orders, measure your own time spent resolving incomplete descriptions before and after improving the part register. Only then can you assess an administrative benefit; the article supplies no assumed failure rate, downtime avoided or payback guarantee.
Best Choice by Scenario
| Situation | Useful next step | Decision boundary |
|---|---|---|
| Original record says Class 8.8, quote says Grade 8 | Return both exact descriptions to the supplier for clarification | No assumed equivalence based on the digit 8 |
| Local source proposes a different class | Request a configuration-specific approved substitution | A higher chart value does not approve a joint |
| Received pack uses an internal part number | Match it to the approved order and assembly record | Do not replace a verified code with a generic label |
| Marking is obscured or incomplete | Ask for reliable part identification from the supplier | No destructive inspection or fitting experiment prescribed |
| Two machines appear to use the same bolt | Request confirmation of common approved spare identity | Visual similarity does not establish interchangeability |
The best choice is the fully identified, approved replacement for the actual assembly. A procurement article cannot select it from a photograph or a partial quote line.
Applications
Distributor spare register: store the supplier’s part code, exact designation, relevant dimensions, material/finish description and machine configuration in distinct fields. Keep source documents linked so later buyers can see why a part was approved.
Cross-border quotation review: preserve the supplier’s original language for the designation alongside any translated purchasing description. Ask whether “grade” is being used generically or refers to a specific US classification. Resolve the question before the purchase line is finalised.
Receiving and stock control: match the delivered pack to the approved order reference. If the label conflicts with the approved specification, record the discrepancy and obtain the responsible supplier’s disposition. Do not relabel an uncertain pack into accepted inventory simply to make the register tidy.
Configuration changes: when an assembly or option changes, ask whether its spare identity changes too. Retaining the old machine-level label without its configuration history can make a once-correct spare description misleading.
FAQ
Are Grade 8 and Class 8.8 two names for the same bolt?
No. Bolt Depot places Grade 8 in its US bolt section and Class 8.8 in its metric bolt section. Keep the grading system and full specification attached to the description.
Does the grade tell me the thread size?
It does not provide a complete dimensional order. Request the approved diameter, thread details, length and head form as separate part information.
Can I choose the stronger entry in the chart?
A mechanical-property comparison does not establish suitability for your assembly. Ask the equipment supplier to approve the actual replacement or proposed substitution.
Does a head marking settle the whole purchase?
It can support identification, but it does not show every dimensional, material, finish or assembly requirement. Match it with the approved part record and supplier evidence.
Which grade do the three WEIMI products use?
No grade is verified here. The public listings establish retail formats, not the fastening specifications of the quoted configuration. Request those details from WEIMI.
Does this guide provide a tightening torque?
No. Use the equipment supplier’s applicable service instructions for the approved assembly. A general grade chart is not an installation procedure.
Final Recommendation
Do not let a shared digit erase a specification boundary. Keep US Grade 8 and metric Class 8.8 distinct in the order record, preserve the original designation and ask the responsible supplier to identify the approved spare for the assembly.
Use the public chart to recognise the ambiguity, then close it with the actual part documentation. A machine shortlist, a strength value and a photograph each answer different questions; none supplies a complete replacement approval by itself.
CTA
Tell WEIMI your preferred vending format, machine configuration and spare-support requirements. Include the original part reference and any conflicting quotation description so the team can respond with configuration-specific information.
Evidence boundary: Bolt Depot supports general grading-system background. The linked WEIMI pages support retail-format descriptions only. No actual machine fastener grade, independent test, assembly load, repair instruction or SEO result is claimed.
