Frequently Asked Questions CNC Machining

Frequently Asked Questions

Here you will find everything you need to understand who we are, what we do and how our online CNC mechanical machining service works.

This guide is designed to answer the most frequently asked questions and give you a complete overview, whether you are a new customer looking to discover our services or you already have experience and are looking for specific insights.

SECTION 1: Who we are and what we do
SECTION 2: How to order
SECTION 3: CNC Design Guide
SECTION 4: Billing and payments
SECTION 5: Shipping
SECTION 6: Other request

Ask GCmill's AI assistant

SEZIONE 1:

Who we are and what we do

GC Mill is a specialized company in precision mechanical machining. We exclusively offer milling and turning CNC services, with a focus on quality, precision and fast delivery times. Our goal is to provide mechanical components to measure for professionals, companies and offices that need high-precision machined parts.

GC Mill offers two main types of machining:

CNC Milling

- Material removal with rotating tools, ideal for creating complex geometries, pockets, grooves, flat surfaces and shaped surfaces.

CNC Turning

- Cylindrical or axially symmetrical parts processing through rotation of the part against fixed tools, perfect for shafts, bushings, pins, connections and revolution components.

CNC stands for Computer Numerical Control (Computerized Numerical Control). It is a subtractive manufacturing technology in which pre-programmed software controls the movement of tools and machinery. Starting from a block of raw material (metal or plastic), the machine removes excess material following the program's instructions until achieving the finished part with extreme dimensional precision.

GC Mill is headquartered in Italy and all work is performed internally at our production facility, equipped with state-of-the-art CNC machining centers of the latest generation. This allows us to guarantee complete control over quality and production times.

The production department is composed of three main areas: mobile spindle lathes (Star), fixed head lathes (Biglia) and machining centers (Okuma, Kitamura and Haas).

Yes, GC Mill offers competitive prices thanks to the optimization of production processes and the use of high-efficiency machinery. You will receive a quote of your project within 24 hours from your request, specifying delivery times and costs.

Yes, GC Mill operates according to ISO 9001 Quality Management System standards, guaranteeing controlled processes, traceability of materials and product conformity.

Yes, you can select this option during the 3D design phase. We can provide a Certificate of Conformity certifying the conformity of products to specific technical specifications agreed upon, with relative dimensional reports.

You can contact us through various channels:

  • Email: info@gcmill.com
  • Phone: +39 3346483088
  • Contact form on the gcmill.com website
  • WhatsApp: +39 3346483088

Our team is available to answer any technical or commercial questions.

SECTION 2:

How to order

The ordering process on GC Mill is simple and fast:

  1. Upload 3D file
    Select your machining and upload your 3D file in STEP, IGES format
  2. Configure the part
    Select the material, quantity, desired finishes and any special tolerances (through a 2D mechanical drawing)
  3. Receive the quote
    A quote will be sent within 24 hours from the insertion of the request
  4. Confirm the order
    After receiving the quote proceed with payment using your preferred method.
  5. Production and shipping
    We make your piece and ship it to the address indicated.

We accept the following 3D file formats:

  • STEP (.stp .step) - recommended format
  • IGES (.igs, .iges)
  • Other CAD formats on request

For CNC machining it is necessary to load 3D solid files.
If you only have 2D drawings (DWG, PDF), contact us for an evaluation.

The maximum file size depends on the geometric complexity. In general, we accept up to 100 MB.
If your file exceeds this limit, please contact us to find a solution.

If you're having trouble uploading the file, check that:

  • The format is among those supported (STEP, IGES, etc.)
  • The file is not corrupt or contains geometric errors
  • The size does not exceed the maximum limit
  • Il modello sia un solido chiuso e non contenga superfici aperte

If the problem persists, contact our technical support.

Yes, by creating an account on our site you can save your quotes and retrieve them at any time. This allows you to compare different configurations and procedures in your order preferences.

Quote prices are valid for a limited period (generally 7-14 days).
We recommend that you proceed with your order within this period to guarantee the quoted price.
For large quantity orders or ongoing projects, please contact us for specific arrangements.

Yes, if you have already placed an order in the past, you can easily reorder the same parts by accessing your order history in your account.
All files and configurations are saved to simplify reorders.

GC Mill is specialized in production, not in design.
However, for simple projects or minor modifications, we can evaluate case by case. If you need a complete design service, we can refer you to qualified partners.

If you have particular requirements for materials not listed in our catalog, please contact us specifying the desired characteristics. We will evaluate the feasibility and provide you with a customized quote.

Unfortunately, once an order is confirmed, it is no longer possible to modify it.

Yes, the delivery dates indicated are calculated based on our standard production times and are respected in most cases. In case of unforeseen circumstances, we will contact you in a timely manner to inform you.

We offer various timing options:

  • Standard - regular production times at the best price
  • Express - accelerated production with surcharge
  • Urgent - maximum priority for critical deliveries

Select the option that best suits your needs during the quote phase.

Absolutely yes.
GC Mill handles both rapid prototyping of single parts and medium to large production runs.
Our system is flexible and adapts to your needs, from a single unit to thousands of components.

Yes, the ordering process is completely manageable online through our website. However, for complex projects, large orders or special requests, we are always available for direct contact via email or phone.

Yes, we serve both companies and private individuals.
Whether you are a manufacturing company, a machine shop, a maker, a hobbyist or a private individual with a personal project, you are welcome at GC Mill

During registration or checkout, select "Company" and enter your complete company details (company name, VAT number, registered office address, legal code, SDI/PEC code for electronic billing).
The invoice will be issued to your company.

If you believe the parts you received are not conform to the specifications, please contact us within 7 days from receipt indicating:

  • Order number
  • Problem description
  • Photos/documentation of non-conformities

Our quality team will analyze the report and provide you with feedback as soon as possible.

By accessing your personal area, in the "My orders" section, you can view all details related to the orders you have placed, including technical specifications, files uploaded and the status of advancement.

SECTION 3:

CNC Design Guide

To obtain the best results from our CNC machining, keep these indications in mind:

  • Internal radii - Internal corners must have a minimum radius equal to the radius of the tool used. For most machining, internal radii of at least 1-3 mm.
  • Wall thickness - Avoid walls that are too thin that could deform during machining. Recommended minimum thickness: 1.5 mm for plastics, 1 mm for metals.
  • Pocket depth - The ratio between pocket depth and width should not exceed 4:1 to ensure optimal machining.
  • Undercuts - Avoid undercuts when possible, as they require special machining tools or multiple operations.
  • Threads - Provide chamfers at the inlet of threads and provide sufficient clearance for the thread tool and outlet thread.

Threads and special tolerances must be indicated in the 3D file or in an attached technical drawing:

  • Threads - Model the hole with the correct pilot diameter and indicate the type of thread in the notes (es M6x1, M8x1.25, UNC, UNF, ecc.).
  • H7/h7 tolerances - Highlight in the 2D drawing the dimensions that require strict tolerances. Standard ISO tolerances (H7 for holes, h7 for shafts).

Yes, before starting production our technical team carries out a feasibility check on the 3D file.

Let's check:

  • Geometric integrity of the model
  • Feasibility of the required work
  • Consistency between specifications and production capabilities

If you have any problems or need clarification, we will contact you before proceeding.

GC Mill offers various finishing options:

  • Sandblasting: Uniform matte finish that hides machining marks.
  • Anodizing (for aluminum): Surface treatment that increases corrosion resistance and allows coloring.
  • Other finishes: Nickel plating, chrome plating, painting, black oxidation, etc.

Contact us for specific requests.

GC Mill works with a wide range of materials:

  • Aluminum - 6082, 7075 (Ergal), and other alloys
  • Steel - C45, S235JR, S355J2, heat-treated alloy steels
  • Stainless Steel - AISI 303, 304, 316L
  • Brass - OT58, OT63
  • Technical plastics - POM (Delrin), PA6, PTFE (Tefl on), PEEK, PVC, PE, ABS

For specific materials not listed, contact us to check availability.

Our standard tolerances are:Le nostre tolleranze standard sono:

  • General tolerance ±0.1 mm for dimensions up to 100 mm
  • ISO tolerances for holes: H7, H8, H9
  • ISO tolerances for shafts: h7, h8, h9, g6, f7
  • Tighter tolerances
  • Available upon request (±0.02 mm, ±0.05 mm)

Always indicate critical tolerances in the attached technical drawing.

Yes, we provide raw material certificates upon request. This can be selected as an option during the 3D upload phase.

SECTION 4:

Billing and payments

GC Mill accepts the following payment methods:

  • Credit/debit card - Visa, Mastercard, American Express
  • PayPal - Safe and immediate payment
  • Advance bank transfer - Payment must be received before production begins
  • Custom payment - For companies with ongoing relationships, it is possible to arrange customized payment conditions.

If you choose bank transfer:

  1. Complete your order by selecting "Bank Transfer" as the payment method
  2. You will receive an email with the bank details (IBAN, account holder, payment reference)
  3. Make the transfer, using the order number as the payment reference
  4. Production will begin once the funds have been credited (1-3 business days)

Yes, GC Mill issues electronic invoices for all orders, as required by Italian law. The invoice is sent to the Exchange System (SDI) and will be available in your tax records (cassetto fiscale).

During registration or during checkout, you will find the fields to enter: Destination Code SDI (7 characters) or PEC address

If you are a private consumer without VAT, the invoice will be issued with recipient code "C.F."

Invoices are available: In your personal area, "Invoices/Documents" section. In the PEC, if you have specified this reception channel.

  • Italian customers with VAT - VAT at 22% charged in the invoice (deductible)
  • Italian private customers - VAT at 22% included in the final price
  • EU customers with valid VAT - VAT not applied (reverse charge), subject to VIES verification
  • Extra-EU customers - VAT not applied (export)

Yes, it is possible to request a pro forma invoice before proceeding with the payment.
The pro forma is useful for requesting internal spending authorizations or for verifying the exact amount before the bank transfer.

Right of withdrawal

The right of withdrawal applies to private consumers as provided for by the Consumer Code.
However, since these are products made to measure according to customer specifications, the right of withdrawal is excluded under art. 59 let. c) of the Decree. 206/2005.

SECTION 5:

Shipping

How much does shipping cost? Shipping costs vary based on:

  • Package weight and dimensions
  • Destination (Italy, EU, Non-EU)
  • Urgency (Standard, Express)

The exact cost is specified during the quote/checkout phase and shown before order confirmation.

Yes, GC Mill ships worldwide. For non-EU destinations, any customs duties and import taxes are the responsibility of the recipient.

Your order will be shipped upon completion of production, by the date indicated in the order confirmation. You will receive an email notification with the tracking number as soon as the package is handed over to the courier.

After shipping, you will receive an email containing:

Tracking number with a direct link to the courier's website to monitor the delivery.

The Delivery Note (DDT) is included inside the package with the goods. A digital copy is available in your personal area.

To process a return:

  1. Contact us within 7 days of receipt, stating the reason
  2. Wait for the Return Merchandise Authorization (RMA)
  3. Carefully pack the goods and ship them to the indicated address
  4. After verification, we will proceed with a replacement or a refund

Note: Returns are only accepted for parts that do not conform to the ordered

If the package has visible damage:

  1. Accept delivery "with reservation" specifying the damage
  2. Take photos of the packaging and contents before fully opening it
  3. Contact us within 24 hours with photos and description of the damage
  4. We will start the process with the courier and send you the replacement goods

If your order is ready before the expected date, we will arrange to ship it ahead of schedule. If you have an urgent need, you can request express production (with supplement) to speed up delivery times.

If the order has not yet been shipped, please contact us immediately with the new address.
Once the package is in transit, any modifications are subject to the carrier's policies and may incur additional costs.

If the package has visible damage:

  1. Accept delivery "with reservation" specifying the damage
  2. Take photos of the packaging and contents before fully opening it
  3. Contact us within 24 hours with photos and a description of the damage
  4. We will start the process with the courier and send you the replacement goods

SECTION 6:

Other questions

Yes, by subscribing to our newsletter you will receive:

  • Updates on new materials and services
  • Exclusive promotions and discount codes
  • Technical guides and design tips
  • You can subscribe via the form on our website or during registration.

Registration is quick and easy:

  1. Click on "Register" or "Create account"
  2. Enter your details (email, password, billing information)
  3. Confirm your registration via the link received by email
  4. Start uploading your files and requesting quotes immediately

On the login page, click on "Forgot password?", enter the email address associated with your account, and you will receive a link to reset your password.

Dopo la spedizione, riceverai un'email con:

Tracking number with a direct link to the courier's website to monitor the delivery.

The Delivery Note (DDT) is included inside the package with the goods. A digital copy is available in your personal area.

To process a return:

  1. Contact us within 7 days of receipt, stating the reason
  2. Wait for the Return Merchandise Authorization (RMA)
  3. Carefully pack the goods and ship them to the indicated address
  4. After verification, we will proceed with a replacement or a refund

Note: Returns are only accepted for parts that do not conform to the ordered

If the package has visible damage:

  1. Accept delivery "with reservation" specifying the damage
  2. Take photos of the packaging and contents before fully opening it
  3. Contattaci entro 24 ore con le foto e la descrizione del danno
  4. We will start the process with the courier and send you the replacement goods

If your order is ready before the expected date, we will arrange to ship it ahead of schedule. If you have an urgent need, you can request express production (with supplement) to speed up delivery times.

If the order has not yet been shipped, please contact us immediately with the new address.
Once the package is in transit, any modifications are subject to the carrier's policies and may incur additional costs.

If the package has visible damage:

  1. Accept delivery "with reservation" specifying the damage
  2. Take photos of the packaging and contents before fully opening it
  3. Contact us within 24 hours with photos and a description of the damage
  4. We will start the process with the courier and send you the replacement goods

GC Mill processes personal data in compliance with the GDPR (EU Regulation 2016/679).
For any other questions not covered in this FAQ, do not hesitate to contact us. The GC Mill team is at your disposal!

Contact Us
Email: info@gcmill.com
Phone / Whatsapp: +39 3346483088

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