What information do you need to quote a custom hydraulic cylinder?

Send bore diameter, rod diameter, stroke, retracted (pin-to-pin) length, working pressure, single- or double-acting design, mounting type at both ends, port size and thread standard, operating environment and estimated annual quantity. A drawing, a sample or a photo of the original nameplate shortens the quotation process.

Can you reproduce an OEM replacement cylinder from a sample?

Yes. Our engineers measure the sample, prepare a technical drawing and send it for your confirmation before machining starts, so interchangeability is agreed in writing before production.

Which standards do your parts and tooling follow?

We machine to the customer drawing in metric or imperial units. Typical references include ISO 6H thread tolerance for hydraulic cylinder nuts, DIN 69872 and JIS B6339 for CNC retention knobs, and ER collet systems for milling tool holders.

Do you supply hydraulic cylinder components separately?

Yes. We supply cylinder heads, pistons, nuts, flanges, bases, integrated barrels, bushings and spherical bearings, as well as hydraulic valve blocks, for cylinder builders and repair workshops.

How are export orders packed and shipped?

Goods are packed with standard export materials to prevent transit damage and shipped by sea, air or express courier according to your preference, with tracking information provided.

How quickly will I receive a reply?

Our sales engineers reply to email enquiries within 24 hours. You can also reach the team directly by phone or WhatsApp.

ODM Retention Knob DIN69872 Suppliers, Manufacturers

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ODM Retention Knob DIN69872 Suppliers, Manufacturers

Retention knob is also called CNC pull stud, as a crucial fastening element in CNC machine tools, retention knob is employed to securely tighten the tool holder. Its primary role is to establish a close connection between the tool holder and the spindle, ensuring stability and precision throughout the precessing operation.

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Product Description

Description

The working principle of the retention knob is that the pull tool mechanism inside the spindle pulls the retention knob, making the tool holder tightly adhere to the end face of the spindle, achieving a rigid connection between the tool holder and the spindle, thereby ensuring the stable progress of the cutting process.

Material of retention knob is usually alloy steel such as 40Cr, 45# steel etc.

Retention knobs come in two styles: Type A and Type B.

Type A features a through-hole, allowing the spindle to discharge water, enabling iron filings to be flushed out by water pressure during drilling. On the other hand, Type B lacks a through-hole but includes a sealing ring groove to prevent coolant leakage from the rear end.

Features

1. High Precision The dimensional accuracy and positional tolerance requirements are strict to ensure the precise fit with the tool holder and the spindle.

2. High Strength It is usually made of high-strength alloy materials. After heat treatment, it exhibits exceptional hardness and wear resistance, enabling it to withstand axial tensile force and vibration during processing.

3. Standardization There are various specifications and models, such as the BT series, CAT series, etc. Different models correspond to different spindle and tool holder specifications.

Parameter

Model No.	D	D1	D2	M	L	L1	L2
LDD-30A(B)	13	9	13	M12	44	24	19
LDD-40A(B)	17	14	19	M16	54	26	20
LDD-45A(B)	21	17	23	M20	65	30	23
LDD-50A(B)	25	21	28	M24	74	34.00	25

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Service

Qingdao Micro Precision Machinery Co., Ltd. has been providing the following CNC tools services to global customers for decades.

Business Type: OEM & ODM Manufacturer
DRW Format: DWG, PDF, IGS, STEP, SLDPRT, SLDDRW, PRT, DRW, DXF, X_T, etc.
Customization: Accepting customization if a certain quantity is reached
QC System: ISO9001: 2008

Our Advantages:

Reliable Quality
Competitive Price
High Precision & Tight Tolerance
Continuous Improvement
Defect-Free Products
On-Time Delivery
Customer Satisfaction
Excellent After-Sales Service

Frequently Asked Questions

What is the difference between Type A and Type B retention knobs?

Type A features a central through-hole allowing coolant to discharge through the spindle to wash away iron filings. Type B does not have a through-hole and is equipped with a sealing ring groove to stop coolant leaks from the back end.

What materials are used to manufacture these retention knobs?

Our pull studs are primarily manufactured from high-strength alloy steels like 40Cr and 45# steel, heat-treated to ensure maximum wear resistance and tensile reliability.

How do I choose the correct retention knob model for my CNC spindle?

Model selection depends on your tool holder taper series (such as BT, CAT, or ISO) and machine spindle requirements. Refer to the parameter dimensions (D, D1, D2, thread size M, and length L) to find the exact match.

Do you accept OEM and customized production orders?

Yes, we are an OEM & ODM manufacturer. Custom orders are accepted based on drawing files (STEP, DXF, DWG, PDF, etc.) once the minimum order quantity is met.

What quality standards are followed during production?

Every production batch undergoes strict quality monitoring under the ISO9001: 2008 management system to ensure accurate tolerances, hardness levels, and defect-free parts.