What does MSTFAB manufacture?

MSTFAB is the international brand of Guangzhou Maisituo Sheet Metal Manufacturing Co., Ltd. It makes drawing-defined sheet metal parts and empty mechanical enclosure shells for OEM buyers, using laser cutting, CNC bending, welding and mechanical assembly. Surface treatments such as powder coating may be coordinated with external partners depending on the order.

Which materials does MSTFAB work with?

Common options include carbon steel, galvanized steel, stainless steel and aluminum. Grade, thickness, dimensions, critical tolerances, hardware, finish and inspection criteria are specified per project on the approved drawing.

What are the MOQ and lead time for custom sheet metal parts?

There is no single MOQ or lead time that applies to every part. MOQ, price, achievable tolerances, lead time, finishing route and inspection deliverables are confirmed in the project quotation and purchase order after the drawing is reviewed.

Does MSTFAB supply electrical components or certified finished equipment?

No. The normal supply scope is fabricated metalwork and empty mechanical housings. Electrical components, wiring, software, system integration and final equipment certification remain with the buyer unless a written quotation or contract explicitly includes them.

How do I request a quote?

Send STEP, STP, DXF, DWG or PDF files with the drawing revision, material and thickness, quantity, critical dimensions, hardware, finish, inspection needs and delivery destination through the RFQ page at https://mstfab.com/contact/.

Sheet Metal Quote Files & RFQ Drawing Guide: STEP, PDF & DXF Hierarchy | MSTFAB

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⚡ Direct Answer: Which Drawing Files Are Required for an Accurate Sheet Metal Quote?

To obtain an accurate, binding sheet metal fabrication quote without engineering delays or hidden surcharges, you must provide a dual-file package: 1) 3D CAD Model in STEP (.stp / .step) format (which governs 3D solid geometry, automated laser blank unfolding, CNC bend collision checking, and cycle time calculation); and 2) Fully Dimensioned 2D PDF / DWG Engineering Drawings (which legally govern critical tolerances, tapped threads, PEM self-clinching hardware part numbers, welding symbols, surface coating RAL codes, and inspection criteria). Never supply pre-unfolded DXF flat patterns for formed parts, as the factory must apply its own tooling V-die widths and empirical bend deduction K-factors.

File Type Authority Hierarchy in Sheet Metal RFQs

Discrepancies between 3D solid geometry and 2D prints are the single greatest cause of quotation delays, tooling holds, and scrap parts in precision manufacturing. MSTFAB establishes a clear contractual hierarchy to eliminate ambiguity:

File Format	Contractual / Production Role	What It Controls	Critical Limitations
3D STEP (.stp, .step, .iges)	Master Geometric Solid	Nominal dimensions, flange angles, hole locations, assembly clearances, press brake backgauge simulation.	Contains no tolerance limits, thread pitches, coating callouts, or grain direction rules.
2D PDF / DWG Print	Legal & Quality Master	GD&T, CTQ bilateral tolerances (±0.05 mm), PEM fastener schedule, tapped holes, powder coat specs, FAI ballooning.	Cannot be parsed directly by automated CAM laser nesting software without manual CAD entry.
2D DXF (Flat Pattern)	Flat Blank Cutting Only	2D profile geometry for 100% flat (non-bent) shim plates, gaskets, and laser-cut brackets.	DO NOT supply for bent parts. Default CAD software K-factors will clash with factory tooling.

Can You Get an Accurate Sheet Metal Quote Without a 2D Drawing?

Many hardware startups and rapid prototyping teams ask: “Can I just submit a 3D STEP file and get an instant quote?”

The realistic answer: For rough budgetary estimates, yes; for production release, absolutely not.

While automated quoting engines can parse 3D STEP files to estimate sheet metal raw material weight and laser cutting perimeter length, relying strictly on 3D models introduces severe manufacturing hazards:

Invisible Threads: 3D CAD files represent tapped holes as plain smooth cylinders. Without a 2D drawing calling out “M4×0.7-6H Thru” or “#10-32 UNF-2B”, the factory laser cutter will cut the clearance diameter rather than the tap drill diameter, making tapping impossible.
Unknown PEM Hardware: Clinch studs and standoffs appear in 3D models as solid geometry. Only a 2D ballooned print specifies the manufacturer part number (e.g., PEM FHS-M4-15 or SO-M3-10ZI).
Default Loose Tolerances: Without designated tolerance callouts, fabricators default to standard commercial tolerances (±0.5 mm or ISO 2768-c). If your mating enclosure requires ±0.1 mm alignment, parts will bind during assembly.

How to Read Sheet Metal Engineering Drawings

Before approving a technical drawing package for manufacturing quotation, design engineers and procurement specialists should review these foundational drafting standards:

1. Bend Lines, Bend Angles & Deduction Marks

Engineering drawings indicate sheet metal bends with centerlines labeled with bend direction (Up / Down), angle (e.g., 90°), and inside bend radius (R). Always verify that inside radii are standardized across the entire part to eliminate press brake tool changeovers.

2. Welding Symbols (AWS A2.4 / ISO 2553)

Standard drawing callouts clarify weld integrity:

Fillet Weld Symbol: A right triangle indicating a lap or T-joint weld, accompanied by leg length (e.g., 3 mm).
All-Around Circle: Requires continuous welding along the entire joint perimeter (essential for IP65/IP66 sealing).
Flush / Ground Smooth Contour: An uppercase flag or flat line above the symbol requiring weld seams to be ground flush for seamless exterior enclosure surfaces.

Avoiding Hidden Costs & Gotcha Surcharges in Fabrication Quotes

When reviewing sheet metal RFQ proposals, lowest initial unit prices often mask expensive backend surcharges. Understanding quote line items protects your procurement budget:

Quoted Surcharge Item	Why Fabricators Bill It	Typical Cost Range	How to Eliminate It in DFM
NRE / Programming Fee	CAM nesting, unfolding flat blanks, and press brake sequence simulation.	50 –250 per assembly	Provide clean, native 3D STEP files with standardized bend radii and uniform gauges.
Custom Tooling Surcharge	Non-standard bend radii or custom louver punches requiring specialized tooling.	300 –1,200	Standardize inside radii to 1.0T or standard factory tooling punch radii (0.8mm, 1.5mm, 3.0mm).
Surface Finish Lot Minimum	Batch powder coating or anodizing tank minimum setup charge.	150 –400 per color	Specify standard inventory RAL colors (e.g., RAL 7035 Light Grey, RAL 9005 Black).
Hardware Insertion Premium	Hand-feeding uncommon or non-stock self-clinching studs into pneumatic presses.	0.20 –0.80 per fastener	Consolidate fastener types; use identical thread sizes (e.g., all M4 studs instead of M3, M4, and M5).

Fiber laser cutting machine cutting precision sheet metal parts from engineering drawings at MSTFAB — Figure 1: High-precision fiber laser profiling blanks derived directly from validated 3D STEP engineering drawings at MSTFAB.

Secure Drawing Handoff & OEM RFQ Submission Checklist

To protect intellectual property and guarantee a rapid 24-hour turnaround, follow MSTFAB’s drawing submission protocol:

Execute Mutual Non-Disclosure Agreement (NDA): MSTFAB executes bilateral NDAs prior to receiving proprietary engineering prints.
Prepare Complete 3D STEP (.stp) Assembly: Include all enclosure sheet metal components in native unfolded solid state.
Supply 2D Vector PDF Drawings: Ensure title blocks state exact material grade (e.g., Stainless Steel 304 #4 Brushed 1.5mm), revision letters, and general tolerances.
State Production Volumes: Indicate prototype quantity (e.g., 5 pcs FAI) and anticipated annual production volume (EAU) to secure volume tiered pricing.
Define Critical Delivery Milestones: Note dock dates, PPAP / AS9102 FAI documentation requirements, and export packaging specifications (e.g., ISPM-15 wooden crates).

Submit Your Drawings for a 24-Hour Engineering Quote

Upload your STEP CAD models and 2D PDF prints to MSTFAB under strict NDA protection. Receive a comprehensive DFM audit, manufacturability report, and firm price within 24 hours.

Upload Drawings for Instant RFQ

Frequently Asked Questions on Sheet Metal Quotes and Drawings

Why should I avoid sending pre-unfolded DXF flat patterns for formed parts?

Each sheet metal fabricator utilizes distinct press brake V-die widths, punch radii, and empirical bend deduction factors (K-factors) calibrated to their specific tooling and sheet material batch. A DXF flat generated by CAD defaults will inevitably cause dimensional errors on the formed finished part. Always provide the folded 3D STEP model so our engineers can calculate exact factory flat blanks.

What happens if there is a dimensional conflict between my 3D CAD and 2D drawing?

Under MSTFAB quality standards, the 2D PDF drawing holds contractual precedence. However, whenever our CAM engineers detect a discrepancy between the 3D solid geometry and 2D printed dimensions, production is held and a formal Engineering Clarification Request (ECR) is submitted to the buyer for written resolution before cutting metal.

How long is an MSTFAB sheet metal quotation valid?

Standard quotations are valid for 30 calendar days. Due to global raw material index fluctuations (e.g., London Metal Exchange pricing for aluminum and stainless steel coils), firm pricing beyond 30 days is subject to raw material market adjustments upon order confirmation.

Can you quote custom sheet metal fabrication from hand sketches or photos?

For preliminary rough order of magnitude (ROM) estimates, clear dimensional sketches with material and quantity notes are acceptable. However, before cutting or bending parts, our in-house engineering team must convert sketches into formal 3D CAD and 2D engineering drawings for client approval.