Do you know which pom plastic ball factory is good ? It's us =Ningyang Xinxin Stainless Steel Ball Manufacture Co.,Ltd
So why it's us ? let us introduce to you as below
POM Plastic Ball Manufacturer: What Actually Decides Whether an Acetal Ball Works
Two buyers can order the same sentence - "10 mm POM ball" - and receive parts that behave completely differently in the same pump. The difference is not the polymer family. It is four decisions made before the first ball is moulded: which POM, which compound grade, which tolerance class, and which measurement is written on the report.
We manufacture solid plastic balls in POM (acetal, Delrin) alongside PP, PA6, PA66, PTFE, PEEK, PS, HDPE, ABS and acrylic, from two plants in Henan and Shandong provinces. This is what we hold ourselves to on POM.
"POM" covers two different polymers, and the choice changes the ball's behaviour in service.
Property
POM-C (copolymer)
POM-H (homopolymer, e.g. Delrin)
Density
~1.41 g/cm³
~1.42 g/cm³
Melting temperature
~166 °C
~175 °C
Tensile strength
~60–67 MPa
~72–76 MPa
Stiffness and creep resistance
Good
Higher
Water absorption (24 h)
~0.05%
~0.25–0.39%
Resistance to hot water, steam and weak alkali
Better
Lower
Centre-line porosity in thick sections
Lower risk
Higher risk
Typical best fit
Pump and valve bodies, humid or alkaline duty, general precision balls
Higher load, higher stiffness, dry-duty bearing and bushing posi
Homopolymer POM is more crystalline, which buys strength, stiffness and creep resistance. Copolymer POM trades a little of that for a wider processing window, better hydrolytic stability and a lower risk of internal porosity at the centre of a thicker ball.
For a lotion-pump or trigger-sprayer check ball, that trade almost always lands on POM-C. A filled dispenser can sit on a shelf for months. POM-C's water absorption of 0.05% over 24 hours at 23 °C means the ball does not swell enough to bind in its seat, and the copolymer's hydrolytic stability survives a product that may be water-based or mildly alkaline. Homopolymer's advantage in tensile strength is not being used in that seat.
The figures above are typical published data for these two polymer families - POM-C values from the Ensinger TECAFORM AH datasheet (DIN EN ISO test methods), homopolymer values from DuPont Delrin datasheets and published acetal comparison data. Test standards and specimen geometry differ between sources, so always confirm against the datasheet of the specific grade being moulded. Grade selection, not family selection, is the number that ships.
Our factory Pom Plastic Ball
01.
Decision two: the compound grade, not just the polymer
Within one family, grades differ in viscosity and additive package, and the differences show up on the shop floor.
A 3/16" ball for lotion-pump service is commonly moulded from a specified acetal grade - FG500P in our production for that duty - held to ±0.02 mm and weighing roughly 0.079 g per piece at that nominal size. Substituting a generic acetal for a specified grade is one of the most common causes of a batch that passes dimensional inspection and still fails in the field, because viscosity governs how the mould fills and where the material's internal stress ends up.
Ask for the grade by name on the quotation. "POM" on a quotation is not a specification.
02.
Decision three: the tolerance class the assembly actually needs
Not every position needs G0, and paying for G0 where G2 is sufficient is wasted money. Three positions account for most of our POM volume:
Pump and sprayer check balls - 3/16" (4.763 mm), ±0.02 mm, typically G1. Surface finish carries as much weight as diameter here: a ball inside its diameter tolerance with a rough surface leaks continuously past the seat.
Telescopic drawer slide elements - 3.90, 3.91, 3.92, 3.94, 3.96, 4.70, 4.74, 4.75 and 4.762 mm, supplied loose at G0 to G2. The 0.02 mm steps are deliberate: slide makers set rail clearance directly from nominal diameter, so a supplier who can hold a narrow step lets the slide designer tune the gap instead of absorbing it in the rail's own tolerance.
Valve sealing balls - 3 mm to 25 mm at G0 to G2, where roundness and surface roughness govern because the sealing band is formed where the ball meets the seat cone.
Grades run from G0 to G3 across our POM range, corresponding to a diameter tolerance of ±0.01 mm to ±0.05 mm. Custom diameters from 0.8 mm to 100 mm are produced to drawing
Decision four: what gets measured, and what gets written down
Diameter alone is a weak guarantee. A ball can sit inside its diameter tolerance and still be out of round, which appears downstream as jamming in a slide or leakage at a seat. Every POM batch we ship is sampled against a control plan and reported on six parameters:
Diameter - against nominal and tolerance class
Roundness - deviation from a true sphere, the parameter that predicts seat sealing
Waviness - lobing that diameter measurement alone will not catch
Surface roughness - the parameter that governs leak rate past a check ball
Lot-to-lot size variation - whether ball number 5,000 matches ball number 50
Hardness - confirmation that the moulded material matches the specified grade
A test certificate stating these six values ships with the goods. A pre-production sample is approved before mass production starts, and final inspection is completed before shipment.
Where processing decides the outcome
Moulding gets the ball close. Grinding makes it round.
POM balls are moulded or machined to near-net size, then taken through secondary precision grinding and polishing. The reasons are specific to the material: POM has a high coefficient of thermal expansion for a rigid polymer and a crystalline structure that keeps changing after the mould opens, so a moulded ball that measures correctly on the day of production will not necessarily measure correctly after it has stabilised. Grinding after stabilisation removes that variable.
Thick sections are the second reason. Homopolymer POM in particular is prone to centre-line porosity as section thickness rises, and a shrink void at the centre of the ball is invisible on a dimensional report while it undermines the ball's compression behaviour. Grinding to size after the material has settled, with an inspection step that looks for internal defects, is how that risk is managed.
Post-processing is performed on the solid body. Drilling, tapping, slotting, chamfering and flat milling are all accepted on POM balls, and unlike a hollow sphere the machined area keeps its core support.
Where POM is the wrong answer
We decline POM orders regularly, because a ball that fails in a customer's valve costs both sides more than the order is worth. Four checks settle it:
Strong acids, chlorine or strong alkali - POM degrades. Specify PP or PTFE.
Continuous service above 100 °C - POM is rated 100 °C long term and 140 °C short term, with a melting temperature of 166 °C for the copolymer. PTFE covers −180 °C to +250 °C.
The ball has to float - arithmetic, not opinion. PP at ~0.905 g/cm³ and HDPE at 0.94–0.97 g/cm³ float in water; POM at ~1.41 g/cm³ does not.
Load per ball exceeds the polymer's compressive strength - POM's compressive strength is 68 MPa at 5% strain (POM-C datasheet values: 20 MPa at 1%, 35 MPa at 2%, 68 MPa at 5%). Beyond that, the answer is a steel ball, not a stiffer plastic.
If the application needs a different material, we say so and quote the alternative from the same plants.
The claim we are prepared to be judged on
We are not going to tell you we make the best POM plastic balls in the world. We will tell you exactly what to measure, and then let you measure it.
Give us the application, the medium, the temperature and the tolerance. We will tell you whether POM-C or POM-H is right, name the compound grade, quote the tolerance class, and send a sample for you to test in your own valve body before you place an order. If a competing ball measures better in your hardware, you have lost nothing but the freight.
That is the only version of "best" that survives contact with a production line.
Free samples, 2–3 days, freight collect. Samples before tooling, every time.
Capacity and documentation
Production runs from two plants - Henan Province, covering 10,000 m² with more than 200 machines, and Shandong Province, covering 5,000 m² with more than 50 machines, roughly 15,000 m² of combined manufacturing space. The two sites can take work from each other, so a loaded line does not move a delivery date.
The manufacturing base dates to 2004 in Ningyang, Shandong. Three entities operate together: Ningyang Xinxin Stainless Steel Ball Manufacture Co., Ltd (production, 2004), Taian Xinxin Import & Export Co., Ltd (export, 2012) and Henan Scole Industry And Trade Co., Ltd (manufacturing and trade, 2016).
Common POM sizes are held in factory stock and dispatched in about four days after payment. Custom sizes and materials run 15–30 days. Minimum order quantity starts at 100 pcs for regular sizes. The plant holds ISO certification, and its plastic balls additionally hold an FDA certificate; PTFE balls have been reported to pass EU REACH testing.
Payment terms include T/T, L/C, Trade Assurance, PayPal and Western Union. Ports of loading include Qingdao, Shanghai and Ningbo.
FAQ
Are you a POM plastic ball manufacturer or a trading company?
A manufacturer. Production runs from two plants: Henan Province (10,000 m², 200+ machines) and Shandong Province (5,000 m², 50+ machines).
What is the difference between POM-C and POM-H?
POM-C is a copolymer: slightly lower density and tensile strength, better resistance to hot water and weak alkali, and lower risk of centre-line porosity in thicker sections. POM-H is a homopolymer: higher density, stiffness, tensile strength and creep resistance, with better performance under sustained load in dry duty. For pump and valve check balls we normally specify POM-C.
Which POM grade do you use for lotion pump balls?
FG500P, held to ±0.02 mm at 3/16" (4.763 mm) nominal, weighing approximately 0.079 g per piece. Grade is confirmed on the quotation.
What tolerance can a POM plastic ball be held to?
G0–G3, corresponding to ±0.01 mm to ±0.05 mm depending on diameter. Custom tighter tolerances can be quoted against a drawing.
What sizes do you produce in POM?
0.8 mm to 100 mm, including custom diameters. Identical stock in other materials is available up to 200 mm in PTFE.
What is reported with each batch?
A test certificate stating nominal diameter, diameter tolerance, roundness, waviness, roughness, lot-to-lot size variation and hardness.
Do you supply samples before an order?
Yes. Samples are free of charge with freight at the buyer's cost, on a 2–3 day lead time. Custom sizes are sampled and approved before mass production.
Do you machine POM balls?
Yes - drilling, tapping, slotting, chamfering and flat milling, all performed on the solid body.
What is the minimum order quantity and lead time?
MOQ from 100 pcs for regular sizes. Stock sizes dispatch in about four days; custom production runs 15–30 days.
Which markets do you export to?
The United States, Germany, France, the United Kingdom, Italy, Belgium, Spain, Brazil, Thailand, Vietnam, Saudi Arabia and Poland, among others.
About US
Ningyang Xinxin Stainless Steel Ball Manufacture Co., Ltd began ball production in Ningyang, Shandong in 2004. The group today manufactures solid plastic balls (POM, PP, PA6, PA66, PTFE, PEEK, PS, HDPE, ABS, acrylic), plastic coated steel balls, stainless steel balls, glass balls, ceramic balls, tungsten carbide balls, aluminium balls, brass and copper balls, hollow plastic balls and stainless steel tumbling media from two plants in Henan and Shandong provinces, China.
Factory address: Xiangfu district, Kaifeng city, Henan province, China.
