Home
Supplier Discovery
Industrial Equipment & Components
Gear
Internal Gear Factories & Companies
Filter
Category
Chemicals
Construction & Decoration
Electrical & Electronics
Manufacturing & Processing Machinery
Metallurgy, Mineral & Energy
More
Management Certification
ISO9001:2008
ISO14001:2004
Others
ISO9001:2015
ISO14001:2015
More
R&D Capacity
OEM
ODM
Own Brand
Others
Annual Revenue
<1 Million USD
1 ~ 2.5 Million USD
2.5 ~ 5 Million USD
5 ~ 10 Million USD
10 ~ 50 Million USD
More
No.of Employees
Less than 5 People
5-50 People
51-200 People
201-500 People
501-1000 People
More
Province & Region
Anhui
Beijing
Chongqing
Fujian
Guangdong
More
about internal gear
Technological Innovation
Reliable Supply Chains
Substantial Manufacturing Capabilities
internal gear
4,000+ factories verified
Suzhou Asia Pacific Intelligent Transmission Technology Co., Ltd
24 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Agma Heat Treatment Large Large Modulus Internal Cylindrical Gears for Industrial Equipment
US$
100.00
-
500.00
1 Piece
(MOQ)
Reduction Planetary Starter Drive Machine Cylindrical Transmission Internal Spur Gear Ring
US$
10.00
-
2,000.00
1 Piece
(MOQ)
Forged Alloy Steel Sun Gear with Internal Splines for Construction & Heavy Equipment
US$
3,500.00
1 Piece
(MOQ)
High Torque Internal Teeth Engranaje for Slewing Bearing Gear Ring
US$
3,500.00
1 Piece
(MOQ)
1/4
Guangzhou Telin Machinery Parts Co., Ltd.
10 yrs
·
5.0
·
Manufacturer/Factory & Trading Company
Send Inquiry
Custom Machine Metal Gear CNC Pinion Helical Axial Spur Bevel Helical Pinion Internal Teeth Gears
US$
3.00
-
20.00
10 Pieces
(MOQ)
OEM Ring Gears Drawings Custom CNC Machining Steel Internal Gear
US$
3.00
-
20.00
10 Pieces
(MOQ)
Buy Miniature Micro Metal Transmission Internal Ring and Pinion Sun Planetary Gear Set for DC Motor
US$
3.00
-
20.00
10 Pieces
(MOQ)
Transmision Part Pto Small Internal Helical Gear Wheel
US$
10.00
-
25.00
10 Pieces
(MOQ)
1/4
Shandong Yahua Machinery Manufacturing Co., Ltd.
15 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Superior Quality 2024 Chinese-Manufactured Internal Half Backplate Linked 28t Trailer Truck Parts Legs Landing Legs Landing Gear
US$
140.00
-
160.00
2 Pieces
(MOQ)
Yahua 28t Internal Backplate Linked Landing Gear Legs Redefining Reliability Landing Gear
US$
140.00
-
160.00
2 Pieces
(MOQ)
Built-in Version Landing Gear/ 28tons / Internal Operation/Landing Jack/Trailer Landing Leg
US$
140.00
-
160.00
2 Pieces
(MOQ)
Durability Redefined: Chinese-Made Internal Backplate Linked 28t Landing Gear Legs
US$
140.00
-
160.00
2 Pieces
(MOQ)
1/4
Wenling Huirong Machinery Co., Ltd.
16 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
OEM ISO9001 Customized Reducer Internal Ring Planetary Transmission Gearbox Gear Factory Bevel Worm Gear for Planetary Wheel
US$
2.00
-
11.00
200 Pieces
(MOQ)
Transmission Parts Manufacture High Speed Car Transmission Parts Spur Ring Internal Teeth Gear
US$
28.00
-
71.00
200 Pieces
(MOQ)
Huirong High Precion Customized Gear Ring Huge Diameter Gear Pinion Internal External Teeth Gear
US$
14.90
-
69.00
400 Pieces
(MOQ)
Customized European Certifications DIN Class 5-8 Gear External and Internal Teeth Spur Driven Reducer Gear
US$
6.90
-
16.90
400 Pieces
(MOQ)
1/4
Hangzhou Xinlan Technology Co., Ltd.
13 yrs
·
4.5
·
Manufacturer/Factory & Trading Company
Send Inquiry
Pinion Rack Round Worm Screw Helical Hypoid Straight Ring Spiral Forged Bevel Spur Differential Steering Internal Box Spline Plastic Nylon Stainless Steel Gear
Negotiable
10 Pieces
(MOQ)
Stainless Steel Ring and Pinion Large Revolution Synchronizer Axle Flywheel Internal Fin Magnetic Cement Mixer Ring Gear Manufacturer Industrial
US$
10.00
-
999.00
100 Pieces
(MOQ)
Internal Gears Stainless Steel Large Internal Flywheel Synchronizer Planetary Manufacturer Plastic Inner Steering Good Price Pinion and Ring Wheel
US$
10.00
-
999.00
100 Pieces
(MOQ)
Ring Bike Bicycle Motor Plastic Spline Shaft Tooth Worm Spur Helical Bevel International Internal Gears Hub Replacement of Sepeda Sturm
US$
10.00
-
999.00
100 Pieces
(MOQ)
1/4
Guangdong Engineering Plastics Industries (Group) Co., Ltd.
17 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Offer Internal Ring Gear and Toothed Gear Professional CNC Router Machine Rack Pinion Gear
US$
10.00
10 Pieces
(MOQ)
Processing Small Modulus Steel Tooth Metal Internal External Gear Set Reducer Planetary Gear
US$
1.00
-
20.00
10 Pieces
(MOQ)
Wholesale Price CNC Machined Nylon Plastic Internal Gear
US$
1.00
-
20.00
10 Pieces
(MOQ)
High Self-Lubrication Delrin Inner Gear POM Plastic Internal Gear
US$
0.10
-
80.00
2 Pieces
(MOQ)
1/4
Jinjiang Feida Machinery Co., Ltd
29 yrs
·
Manufacturer/Factory
Send Inquiry
High-Efficiency Transmission Internal Gear Ring Assembly
US$
0.001
1 Piece
(MOQ)
Internal Gear Rings for Motorcycle Transmissions
US$
0.001
1 Piece
(MOQ)
Spur Gear for Gear Pump - External/Internal Meshing
US$
0.001
1 Piece
(MOQ)
Internal Gear Ring Assemblies for Agricultural Machinery
US$
0.001
1 Piece
(MOQ)
1/4
Shandong Pingchuan Machinery Equipment Co., Ltd.
11 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Customized Hard Surface Automotive Industry Finally Metallurgical Helical Girth Internal Gear
US$
10.00
-
40.00
10 Pieces
(MOQ)
Pinion Rack Round Worm Screw Helical Hypoid Straight Ring Spiral Forged Bevel Spur Differential Steering Internal Box Spline Plastic Nylon Stainless Steel Gear
US$
10.00
-
20.00
10 Pieces
(MOQ)
Customized Heavy-Duty Helical Girth Internal Gear for Automotive Applications
US$
10.00
-
40.00
10 Pieces
(MOQ)
Customized Minimal Backlash Automotive Industry Finally Metallurgical Helical Girth Internal Gear
US$
10.00
-
40.00
10 Pieces
(MOQ)
1/4
Hebei Lite Engineering Machinery Co., Ltd.
15 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Custom Machine Metal Gear Manufacturing Supplier, CNC Pinion, Helical Axial Spur Gear, Internal Gear, Industrial Gearbox
US$
40.00
-
160.00
1 Pieces
(MOQ)
OEM Custom Machine Metal Gear Manufacturing Supplier CNC Pinion Helical Axial Spur Gear Internal Gear
US$
50.00
-
500.00
1 Pieces
(MOQ)
Forged Heavy-Duty Pinion Internal Gears, Custom Large-Diameter Internal Gears, Large Hardened Spur Gears Suitable for Industrial Machinery
US$
40.00
-
500.00
1 Pieces
(MOQ)
Forged Heavy-Duty Small Internal Gears, Custom Large-Diameter External Gears Large Spur Gears, Steel High-Efficiency Helical Gears
US$
145.00
-
199.00
1 Pieces
(MOQ)
1/4
Jiangyin Ke 'an Transmission Machinery Co., Ltd
Send Inquiry
China Manufacturer Forged Helical Gear Internal Gear
US$
40.00
-
60.00
1 Piece
(MOQ)
Ultra-Thin Internal Gear with Five-Level Precision Under The Heat Treatment Carburizing and Quenching Process
US$
1,200.00
-
1,850.00
1 Piece
(MOQ)
High Precision Bevel Internal Spur Pinion Gear Manufacturing
US$
40.00
-
60.00
1 Piece
(MOQ)
Customize Precision CNC Machining Turning Driving Gear
US$
40.00
-
60.00
1 Piece
(MOQ)
1/4
Jinan Hongtu Forging Co., Ltd
9 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
OEM Custom Steel Plant Tooth Material Origin Shape Industries Angle External Internal Ring Gears CNC Machining Parts
US$
6.00
-
10.00
500 Pieces
(MOQ)
Forged Alloy Steel Big Internal Ring Gear Swing Gear for Wind Power or Rotary Conveyor
US$
6.00
-
10.00
500 Pieces
(MOQ)
Manufacturer CNC Machining High Hardened Professional Forging Steel Internal Gear Ring
US$
6.00
-
10.00
500 Pieces
(MOQ)
Forged Round Ring Internal Gears Sheet Metal Forging Metal Finish Machining
US$
6.00
-
10.00
500 Pieces
(MOQ)
1/4
Hebei Ying Xing Gear Co., Ltd.
Send Inquiry
Heavy-Duty Ø 270mm M3.5 Z62 Internal Gear for Mining Reducers
US$
100.00
-
1,000.00
1 Piece
(MOQ)
Module 3.5 Z49 Internal Small Gear Ring for Machine with Grinding
US$
50.00
-
100.00
1 Piece
(MOQ)
Customized M8.4667 Z90 854mm High Quality Internal Gear Ring with 40CrNiMoA Material for Oil Machine
US$
10.00
-
1,000.00
1 Piece
(MOQ)
Custom Internal Ring Gear for Oil Drilling Applications
US$
50.00
-
200.00
1 Piece
(MOQ)
1/4
Shenzhen Hefa Gear Machinery Co., Ltd.
17 yrs
·
5.0
·
Manufacturer/Factory & Trading Company
Send Inquiry
Manufacturers Supply Variety of Specifications Wholesale High-Precision Internal Gear Ring
US$
2.00
-
15.00
10 Pieces
(MOQ)
Ihf OEM Customize Steel Aluminum Small Internal Ring Gears
US$
2.00
-
17.00
10 Pieces
(MOQ)
OEM ODM Customized Nylon Transmission Internal Spur Plastic Gear for 3c Industry Equipment
US$
0.50
-
99.00
10 Pieces
(MOQ)
Forged Bevel Spur Differential Steering Internal Box Spline Plastic Nylon Stainless Steel Gear
US$
2.00
-
15.00
10 Pieces
(MOQ)
1/4
Zhangjiagang Kehua Gear Co., Ltd.
19 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Robust Steel Part with Mining Equipment Power Transmission Internal Gear Assembly
US$
40.00
-
100.00
10 Sets
(MOQ)
Internal Spline Shaft Mount Precision Helical Cylindrical Gears
US$
40.00
-
100.00
10 Pieces
(MOQ)
Low Noise Mechanical Component with Manufacturing Machinery Efficiency Internal Gear Assembly
US$
40.00
-
100.00
10 Sets
(MOQ)
Accurate Engineered Component with Agricultural Machinery Drive Application Internal Gear Assembly
US$
40.00
-
100.00
10 Sets
(MOQ)
1/4
Shaanxi Huawei Technology Co., Ltd
25 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Forged Alloy Steel Big Internal Ring Gear for Wind
US$
300.00
1 Piece
(MOQ)
Precision Internal Ring Gears Machining for Customized Wind Power Applications
US$
300.00
1 Piece
(MOQ)
Customized CNC Machining for High-Performance Internal Ring Gears Solutions
US$
300.00
1 Piece
(MOQ)
China Customized Forged Alloy Steel Big Internal Ring Gear for Wind
US$
158.00
1 Piece
(MOQ)
1/4
Changzhou Zhihai Machinery Co., Ltd.
5.0
Send Inquiry
Precision Internal Spur Gears for Auto and Motorcycle Applications
US$
15.00
-
50.00
10 Pieces
(MOQ)
Wear-Resistant Hardware Part Turret Rack Internal Gears for Wood Working Machinery
US$
10.00
-
500.00
100 Pieces
(MOQ)
High-Strength Hardware Part Turret Rack Internal Gears for Wood Working Machinery
US$
10.00
-
500.00
100 Pieces
(MOQ)
OEM ISO9001 Customized Reducer Internal Ring Planetary Transmission Gearbox Gear
US$
3.00
-
8.00
1,000 Pieces
(MOQ)
1/4
Shaoxing Guoteng Auto Spare Parts Co., Ltd.
13 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Non-Standard Internal Ring Teeth Gear for Automotive & Machinery Applications
US$
0.02
-
5.00
5 Pieces
(MOQ)
Custom Pm Powder Metallurgy Sintered Internal Spline Teeth Transmission Internal Gear Hydraulic Pumps Splined/Spline Hubs
US$
0.50
-
100.00
100 Pieces
(MOQ)
Custom Iron-Based Pm Gears with Internal Ring Teeth for Mechanical Systems
US$
0.03
-
3.00
5 Pieces
(MOQ)
Precision Powder Metallurgy Gears with Internal Ring Teeth with Pm Process
US$
0.03
-
5.00
5 Pieces
(MOQ)
1/4
Luoyang Deyu Machinery& Technology Co., Ltd.
9 yrs
·
Manufacturer/Factory & Trading Company
Send Inquiry
Forged Alloy Steel Big Internal Ring Gear for Rotary Conveyor
US$
40.00
-
50.00
1 Piece
(MOQ)
Factory Custom OEM High Quality Steel Inner Internal Ring Gear
US$
40.00
-
50.00
1 Piece
(MOQ)
Customized High Quality Internal Straight Gear Inner Spur Gear
US$
40.00
-
50.00
1 Piece
(MOQ)
Custom CNC Precision Processing Ball Mill Slewing Internal Ring Gear with ISO9001
US$
40.00
-
50.00
1 Piece
(MOQ)
1/4
Zhongshan Aoying Powder Metallurgy Technology Co., Ltd.
16 yrs
·
5.0
·
Manufacturer/Factory & Trading Company
Send Inquiry
Heat Treatment Powder Metallurgy Sintered Iron Internal Gear Optimized for Lock Mechanism Drive Systems
US$
1.30
-
1.80
100 Pieces
(MOQ)
Precision Spur Gear Stainless Steel High-Accuracy Large 18.95*H8.5mm Internal Gear for Construction Core Components
US$
0.40
-
1.00
100 Pieces
(MOQ)
Powder Metallurgy Pressed Sintered Iron Based Internal Gear Ring for Smooth Meshing
US$
1.30
-
1.80
100 Pieces
(MOQ)
Factory Customized Sintered Internal Gear External Gears Double Spur Gears for Gearbox
US$
0.30
-
1.00
1,000 Pieces
(MOQ)
1/4
Taizhou Kecheng Automotive Components and Parts Co., Ltd.
Send Inquiry
Micro Differential Custom Internal Double Spur Gear
US$
0.10
-
2.00
1,000 Pieces
(MOQ)
Customized Powder Metallurgy High Precision Internal Ring Gear for Planetary Gearbox
US$
0.10
-
5.00
100 Pieces
(MOQ)
Sintered Powder Metallurgy Supplier Products Gearbox Parts Internal Hub Gear for Automotive Transmission
US$
0.50
-
5.00
1 Piece
(MOQ)
Customized Gearbox Gear Pump Factory Internal Double Steel Sintered Powder Metallurgy Parts
US$
0.50
-
5.00
1 Piece
(MOQ)
1/4
Shandong Meide Import and Export Co., Ltd.
Send Inquiry
Bull Forging Steel Ring Rotary Klin Blank Flange by Rolling Machine Alloy Spur Die Gears Internal Outer Gear
US$
1.00
-
1.80
100 Pieces
(MOQ)
5083 Rolled Ring for Wind Turbine 4130 Alloy Steel 35CrMo Hot 42CrMo Large Diameter Internal Gear Forging
US$
1.00
-
2.50
10 Pieces
(MOQ)
Customized Material Forging Ring Big Steel Large Custom Slewing Rolling Metal Wheel Girth Internal Gear
US$
1.00
-
1.80
100 Pieces
(MOQ)
Industrial Excavator Forged Drive Parts Tractor Wheel Internal Metal 42CrMo4 Gear
US$
1.00
-
2.50
10 Pieces
(MOQ)
1/3
Maanshan Kingrail Technology Co., Ltd.
6 yrs
·
5.0
·
Trading Company
Send Inquiry
China Manufacturer CNC Machining Steel Internal/Inner Gear Ring
US$
1,000.00
-
2,000.00
1 Piece
(MOQ)
Custom Large Forged Internal Rotating Double Helical Herringbone Spur Bull Gear Ring
US$
1,000.00
-
2,000.00
1 Piece
(MOQ)
Rotary Kiln Internal Girth Gear OEM Ball Mill Pinion Gear Wheel for Cement Mixer Parts
US$
300.00
-
900.00
1 Piece
(MOQ)
Industial Big Size Steel Internal Ring Gear Machined Transmission Gear for Concrete Mixers
US$
300.00
-
900.00
1 Piece
(MOQ)
1/4
Wier (Beijing) New Materials Co., Ltd.
5.0
Send Inquiry
High-Strength Alloy Steel Internal Combustion Engine Spur Gear with Wear-Resistant Coating
US$
100.00
-
800.00
1 Piece
(MOQ)
Customized CNC Machining Alloy Steel Internal Combustion Engine Gear Helical Gear
US$
10.00
-
40.00
1 Piece
(MOQ)
OEM Custom Planetary Gear Internal Gear Ring High Efficiency
US$
10.00
-
40.00
1 Piece
(MOQ)
Eco-Friendly Alloy Steel Internal Combustion Engine Spur Gear – Recyclable Material
US$
100.00
-
800.00
1 Piece
(MOQ)
1/4
Changzhou Kadi International Trade Co., Ltd.
8 yrs
·
Trading Company
Send Inquiry
Powder Metallurgy Copper Alloy Internal Gear for Motors
US$
0.02
-
0.50
10,000 Pieces
(MOQ)
Powder Metallurgy Iron - Based Internal Gears for Washing Machines
US$
0.02
-
0.50
10,000 Pieces
(MOQ)
Metal Injection Molding Iron - Based Gear for Motorcycle Parts
US$
0.02
-
0.50
10,000 Pieces
(MOQ)
High Quality Powder Metallurgy Sintered Metal Braiding Gear
US$
0.02
-
0.50
10,000 Pieces
(MOQ)
1/4
Anshan Metal Co., Ltd.
10 yrs
·
Trading Company
Send Inquiry
Large Internal Girth Gear, Inner Gear, OEM Internal Gear
US$
2,400.00
-
4,500.00
1 Ton
(MOQ)
Manufacturer Forging Heavy Pinion Inner Gear Customized Large Diameter Internal Gear Wheel Large Spur Gear
US$
100.00
-
2,500.00
1 Piece
(MOQ)
Generator-Use High-Quality Industrial Flywheel
US$
700.00
-
1,200.00
1 Ton
(MOQ)
Wear-Resistant Custom Machinery Flywheel
US$
700.00
-
1,200.00
1 Ton
(MOQ)
1/4
Qingdao King Machinery Co., Ltd.
5 yrs
·
5.0
·
Trading Company
Send Inquiry
Precision Helical Gear Cylindrical Internal Transmission Cast Steel Gear Shaft for Agricultural Machinery
US$
50.00
-
120.00
1 Piece
(MOQ)
Customized Precision Gears for Spru Bevel Gear Cylindrical Helical Internal Gears for Agricultural
US$
50.00
-
120.00
1 Piece
(MOQ)
Precision Helical Bevel Gear Cast Steel Internal Gear Shaft for Industrial Agricultural Machinery
US$
50.00
-
200.00
1 Piece
(MOQ)
Professional Customized High Precision Sprul Bevel Internal Gear for Industrial Machinery
US$
50.00
-
150.00
1 Piece
(MOQ)
1/4
KOBO Advanced Materials Co., Ltd.
8 yrs
Send Inquiry
OEM Ring Gears Drawings Custom CNC Machining Steel Internal Gear
US$
2.00
-
50.00
10 Pieces
(MOQ)
Powder Metallurgy Transmission Precise Iron Sintered Industrial Internal Ring and Pinion Planetary Gear
US$
2.00
-
50.00
10 Pieces
(MOQ)
CNC Machining Customized High-Performance Internal Ring Gears for Wind Power Products
US$
2.00
-
50.00
10 Pieces
(MOQ)
Custom China Factory Powder Metallurgy Transmission Precise Iron Sintered Industrial Internal Ring and Pinion Planetary Gear
US$
2.00
-
50.00
10 Pieces
(MOQ)
1/4
Dongguan Quality Innovation and Technology Co., Ltd
5.0
Send Inquiry
OEM Europe/USA Precision CNC Turning Steel Internal Tooth Spur Gear Ring Gears
US$
2.00
-
10.00
100 Pieces
(MOQ)
OEM Europe/USA Client Customized CNC Turning Steel Internal Tooth Spur Gear Ring Gears
US$
2.00
-
10.00
100 Pieces
(MOQ)
Precision Milling Turning Steel Transmission Helical Gears and Helical Internal/External Gear Ring Gear
US$
2.60
-
4.00
1,000 Pieces
(MOQ)
Customized Precise Transmission Iron Steel Ring Inner Annular Gear for Electric Tools Transmission
US$
2.60
-
4.00
1,000 Pieces
(MOQ)
1/4
Ningbo High-Tech Park Unimolding Rubber & Plastic Parts Co., Ltd.
22 yrs
·
Trading Company
Send Inquiry
Internal Gear/Internal Gear Ring for Auto Starter/ OEM Slewing Ring Bearing Internal Ring Gear
US$
0.10
-
3.00
500 Pieces
(MOQ)
Internal Gear/Gear Reducer/Transmission Gear/OEM High Precision Transmission Parts Internal Thread Worm Gear
US$
1.00
-
3.00
500 Pieces
(MOQ)
Internal Gear and Spur Gear/High Precision Metal Spur Gear/Custom Spur Gear
US$
1.00
-
2.00
500 Pieces
(MOQ)
Internal Gear/Carbon Seel Engine Starter Flywheel Internal Ring Gear/Forging Internal Gear Ring
US$
0.80
-
1.20
500 Pieces
(MOQ)
1/4
SHIJIAZHUANG HSPT CO., LTD.
3 yrs
·
5.0
·
Manufacturer/Factory & Trading Company
Send Inquiry
Custom Machine Metal Gears Manufacturing Suppliers CNC Pinion Helical Axial Spur Bevel Helical Pinion Internal Teeth Gears
US$
1.20
-
1.80
10 Pieces
(MOQ)
China Supplier Machining Custom CNC Plastic Planetary Gears Sets Nylon Internal Rack and Pinion Gear Factory
US$
1.20
-
1.80
10 Pieces
(MOQ)
Spiral Bevel Gear Hypoid Helical Cut Gears Plastic Spur Bronze Screw Stainless Steel Brass Differential Internal Spline Shaft Ring Gear Herringbone Aluminum
US$
1.20
-
1.80
10 Pieces
(MOQ)
Custom CNC Pinion Helical Axial Spur Bevel Gears Steel Internal Teeth Gears Manufacturing Suppliers
US$
1.20
-
1.80
10 Pieces
(MOQ)
1/4
1
155
Hot Products
Worm Gear
Gear Shaft
Machinery Gear
Plastic Gear
Drive Gear
Control Gear
Aluminium Gear
Internal Components
Related Manufacturers & Supplier
Car Gear Factories
Transmission Gear Factories
Side Gear Factories
Internal Helical Gear Factories
Hydraulic Internal Gear Pumps Manufacturers
Marine Gear Manufacturers
Planetary Gear Motor Manufacturers
Starter Gear Manufacturers